Get live activity (sub-agent visibility)

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, and the description reinforces this. The description goes beyond by detailing the exact filesystem signals included (dirty files, commits, worktrees, .fb-progress files), and explains behavior in all-projects mode (quiet projects returned as plain name strings). It also provides context about sub-agent conventions (e.g., .fb-progress file usage).

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is a single paragraph that is front-loaded with the purpose but then delves into detailed explanation of data content and usage. While every sentence adds value, the description is somewhat verbose and could be more concise. However, it is well-structured with the key information presented early.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given no output schema, the description adequately explains the return shape: per repo information (dirty files, commits, worktrees, .fb-progress, recently-modified files, board-side signals). It also covers the all-projects mode and provides operational context about sub-agent conventions. The description is complete enough for the tool's complexity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all 4 parameters. The description adds marginal value beyond the schema: it mentions that omitting 'project' gives an all-projects rollup, which the schema implies. However, the description does not add detailed semantics beyond what is in the schema, so a baseline score of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool is 'Read-only git/filesystem ground truth about what coding sub-agents are doing RIGHT NOW'. It specifies the resource (filesystem activity of sub-agents) and scope (one project or rollup across all projects). It distinguishes from siblings like get_agent_monitor by explaining that this tool provides filesystem-level data rather than board-level data.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly says 'Use this for stalled-ticket triage (get_agent_monitor flags a stall from board events; this answers "but is anything actually moving?") and for a cross-project "what's live right now" rollup on Mission Control.' It also explains when not to use it: 'Sub-agents deliberately never write the board mid-flight... the board itself has nothing new to say — the filesystem is the only truth.' This provides clear context for tool selection.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.