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Tools reference

Every tool Mnemo AI can call, with its parameters, defaults, and limits.

You never call these yourself — the model does, and the assistant prints each call as it happens. This page is for reading those calls, understanding why one was refused, and knowing which parameters exist. For the toggles and prompts that govern whether a call runs at all, see Control what Mnemo AI can do.

31 tools in 17 groups. Twenty-three are always available; the remaining eight appear only when a feature is enabled.

I want to know Go to
Which file-reading modes exist fs_read modes
How an edit is applied Write and edit files
Why a write was refused Read-before-write
What a search flag does Search
Which tools need a feature toggle Conditional tools
What is refused outright Safety floor

Read files

Tool Parameters Purpose
fs_read path (required), mode = "Line", start_line = 1, end_line = -1, pattern = "", context_lines = 2, depth = 0 Read a file — or list a directory — in one of eight modes.

A successful read also records that the file was read, which is what later permits a write to it. Listing a directory records nothing.

fs_read modes

mode selects the reader. Each mode uses only some parameters; the rest are ignored.

mode What it does Uses
"Line" Streams a line range with a cat -n gutter. Negative values count from the end of the file. Binary and image files fail fast with a pointer to describe_image. start_line, end_line
"Search" Literal, case-insensitive substring search with N lines of context per hit. Not a regex. pattern, context_lines
"Directory" Recursive listing. Skips dot-entries. depth: 0 is the current level only. depth
"CSV" Sniffs the delimiter — , first, then ;, tab, or pipe — and returns columns plus rows up to the token cap. —
"JSON" Reads the file, applies the line range, then validates the syntax of what is left. start_line, end_line
"JSONL" Same reader as "JSON"; per-line validation is chosen by the .jsonl file extension, not by this value. start_line, end_line
"PDF" Page-marked text extraction. Large documents are offloaded to RAG or chunk-summarized. —
"DOCX" Paragraph text. Rejects any file not ending in .docx. Tables, headers, and footnotes are not extracted. —

Any other value returns an error listing all eight. One thing to know: a partial line range on a .json file fails validation, because the syntax check runs after the slice — half an object is not valid JSON.

Limits. Output is capped by DOC_MAX_TOKENS (16384 in the shipped config; 8192 when the key is absent) and truncation appends [TRUNCATED - Content exceeds token limit]. PDF and DOCX offload to RAG above RAG.MAX_TOKENS (8192), chunking at RAG.CHUNK_TOKENS (1024).

Write and edit files

Tool Parameters Purpose
fs_write path (required), command (required), file_text = "", old_str = "", new_str = "", insert_line = 0, summary = "" Create a file, or modify one via a four-command interface.
file_edit file_path (required), old_string (required), new_string (required), replace_all = False Exact-string replacement, validated for existence and uniqueness.

Both preserve the file's existing encoding, BOM, and line endings. Note the parameter names differ: fs_write takes path, file_edit takes file_path.

fs_write commands

command Requires Behavior
"create" file_text Creates parent directories and overwrites an existing file.
"str_replace" old_str, new_str Fails if the text is absent, and fails if it appears more than once. There is no replace_all here.
"insert" insert_line, new_str Inserts after the given line. 0 prepends; the maximum is the file's line count.
"append" new_str Appends, inserting a leading newline if the file doesn't end with one.

file_edit matching

old_string must match the file byte-for-byte. Two behaviors are worth knowing because they change what you should paste:

  • Line-number gutters are tolerated. If the match fails, the tool strips a leading cat -n gutter from old_string and retries — so text copied straight out of an fs_read result still matches. new_string is never altered.
  • Ambiguity is an error, not a guess. More than one occurrence with replace_all=False fails and returns up to three sample locations with line numbers. replace_all=True replaces all of them; False replaces the first.

A replacement that would change nothing is also refused.

Read-before-write

An existing file must be read before it can be modified. This is enforced server-side, so it applies however the tool is driven, and it produces one of two errors:

Error field Meaning Fix
must_read_first The file was never read this session. Read it, then retry.
stale_read It changed on disk since it was read. Read it again, re-derive the edit.

Creating a new file needs no prior read. A successful write counts as a read, so consecutive edits to the same file don't trip the gate. The record is keyed by resolved path and modification time, and lasts for the session.

Tool Parameters Purpose
glob_search pattern (required), path = None, max_results = 1000, sort_by_mtime = True, include_ignored = False Find files by name. Newest first by default.
grep_search pattern (required), path = None, file_pattern = None, case_insensitive = False, output_mode = "files_with_matches", context_lines = 0, context_before = 0, context_after = 0, max_results = 100, offset = 0 Search file contents via ripgrep.

path defaults to the current working directory. max_results: 0 means unlimited.

glob_search skips eleven noise directories unless include_ignored=True: .git, .idea, .mypy_cache, .pytest_cache, .ruff_cache, .tox, .venv, __pycache__, build, dist, node_modules. With sort_by_mtime=True it collects then sorts, so a capped result really is the newest N — at the cost of scanning everything, up to a ceiling of 100,000 matches. sort_by_mtime=False stops early and is faster.

grep_search takes three output_mode values: "files_with_matches" (default), "content", and "count". Context flags apply only in content mode, where context_before/context_after override the symmetric context_lines.

max_results counts different things per mode

In content mode it caps matches (context lines ride along, extra). In files_with_matches and count mode it caps files. offset pages through a stable order in both cases — results are sorted by path so paging is meaningful.

Limits. Lines are truncated at 500 characters with a … [+N chars] marker. The ripgrep subprocess times out after 30 seconds. ripgrep is required — it is not optional and there is no fallback; without it grep_search returns an install hint.

Run commands

Tool Parameters Purpose
execute_bash command (required), timeout = 30 Run a shell command, returning stdout, stderr, and exit status.

The command runs in its own process group, so a timeout kills the whole tree rather than just the shell. Output is capped at 30,000 characters, middle-truncated to keep the beginning and the end.

Every command passes the safety floor first, and — unless you turn it off — asks you to confirm.

Run work in the background

Seven tools, for commands too slow to wait on.

Tool Parameters Purpose
start_background_task command (required), description = "", working_directory = "" Launch a detached command; returns an 8-character task id.
get_task_status task_id (required) Status, timings, return code, log path.
get_task_output task_id (required), tail_lines = 50 Captured output. 0 or less returns the whole log.
list_background_tasks include_completed = True All tasks, newest first, plus a summary count.
cancel_background_task task_id (required) Kills the process group. Only works on a running task.
wait_for_task task_id (required), timeout_seconds = 300 Blocks until the task finishes.
clear_completed_tasks (none) Drops finished tasks from the registry and deletes their logs.

Statuses are pending, running, completed, failed, error, and cancelled. Output goes to ~/.mnemoai/tasks/<task_id>.log; logs older than 7 days are swept at startup. The working directory is checked against the same path policy as a file write.

Track multi-step work

Tool Parameters Purpose
todo_write todos (required, JSON array), scope = "default" Validate and replace the list for a scope.
todo_read scope = "default" Read the current list.
todo_clear scope = "default" Delete the list.

Each item needs all three keys:

{
  "content": "Task description (imperative form)",
  "status": "pending|in_progress|completed",
  "activeForm": "Running tests"
}

status must be one of pending, in_progress, completed. Exactly one item should be in_progress; more than one logs a warning but is not rejected.

scope lets separate workstreams keep separate lists. It is sanitized to [A-Za-z0-9_-] and truncated to 64 characters, so two labels differing only in punctuation can collide. Lists are also namespaced per running instance, so two terminal tabs don't overwrite each other — and todo_read must use the same scope string as the write.

Work with git

Tool Parameters Purpose
git_safe command (required, no git prefix), allow_dangerous = False, reason = "" Run a git command through the safety classifier.
git_status_safe (none) Branch, change count, ahead/behind, warnings.
git_commit_safe message (required), add_all = False, add_files = "", amend = False, allow_empty = False, allow_dangerous = False, reason = "" Stage and commit, with amend-safety checks.

allow_dangerous=True always requires a reason. Arguments are split with shlex, so quoted commit messages survive intact. See Keep git operations recoverable for what is blocked outright versus what asks first.

Ask, plan, and delegate

Tool Parameters Purpose
ask_user_question question (required), options (required) Hand a decision back to you as a picker.
exit_plan_mode plan (required, markdown), allowed_bash = None Present a finished plan for approval and leave plan mode.
spawn_agent agent_type (required), prompt (required), description = "", run_in_background = True Delegate a self-contained task to a fresh sub-agent.
resume_agent agent_id (required), prompt (required), run_in_background = True Continue a previous sub-agent with a follow-up, keeping its context.

agent_type is general-purpose (full toolset), explore (read-only), or plan (read-only) — plus any custom agent in ~/.mnemoai/agents/. Entries in allowed_bash become pre-approved commands, matched by prefix, so an approved plan's pytest also covers pytest tests/unit.

These four are handled by the client, not the tool server — they need your terminal. Concurrency is capped by LLM.SUBAGENT_MAX_CONCURRENCY (4).

Conditional tools

These register only when their feature is on. A tool that isn't registered is invisible to the model.

Tool Enabled by Default
memory ENABLE_MEMORY on
use_skill ENABLE_SKILLS on
list_documents, search_in_documents, clear_documents ENABLE_RAG off
web_search ENABLE_WEB_SEARCH and a BRAVE_API_KEY off
web_crawler ENABLE_WEB_CRAWL off
describe_image a working VISION_MODEL_ID — there is no ENABLE_ flag off

The defaults above are what the code does when a key is absent from config.yaml. The setup wizard writes a different, more generous set — see the toggle table in Usage.

Tool Parameters Purpose
memory action (required), text = "", old_text = "" Maintain MEMORY.md: add, replace, or remove.
use_skill name (required), arguments = "" Load a skill's full instructions into context.
search_in_documents query (required), top_k = 8 Hybrid semantic + keyword search over indexed documents.
list_documents (none) Indexed document ids and chunk counts.
clear_documents (none) Drop all vectors and the keyword index.
web_search query (required), search_lang = "en", num_results = 10, freshness = "", country = "", ui_lang = "" Brave Search results.
web_crawler url (required) Fetch a page as markdown, or index it into RAG when large.
describe_image image_path (required), question = "Describe this image in detail." Answer a question about an image.

Notes on the ones with sharp edges:

  • memory replaces and removes by substring: old_text need only uniquely identify one entry. Ambiguity is an error. MEMORY.MAX_CHARS (2200) is a hard cap — an add that would overflow it fails and asks for consolidation.
  • web_search clamps num_results to 1–20. freshness accepts pd, pw, pm, py, or a YYYY-MM-DDtoYYYY-MM-DD range; it, country, and ui_lang are only sent when non-empty. Safe search is off.
  • web_crawler checks the URL against the SSRF policy before fetching. Large pages return no content at all — instead you get a chunk count and a pointer to search_in_documents. Inline results are capped at 100,000 characters; the page timeout is WEB_CRAWL.PAGE_TIMEOUT_MS (60000).
  • describe_image accepts .png, .jpg, .jpeg, .gif, .bmp, .webp.
  • use_skill substitutes $ARGUMENTS and ${SKILL_DIR} into the skill body.

See also