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

Annotations already cover the safety profile (readOnly, idempotent, openWorld, non-destructive), yet the description still adds real behavioral context: default filtering of expired sessions, page-size bounds, pinning/closing-soon ordering, and the startAtKnown=false caveat about restating dates. It does not describe the response envelope or cursor semantics in any depth, which is the one remaining gap.

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?

Purpose is front-loaded and the rest is telegraphic, with arrows compressing the workflow. It is a dense run of clauses without clear separation, which costs a little parseability, but virtually every clause carries distinct information.

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?

For a filtered, paginated feed with no output schema, the description covers defaults, ordering, pagination bounds, filter interaction, dedupe, and edge-case handling. An agent has everything needed to call it correctly.

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 coverage is 100%, so the baseline is 3, but the description adds meaning the schema lacks: that kind filtering interacts with q, and that an empty q result should be retried without the keyword per the hint. The q search-scope and limit/default statements largely restate the schema and earn no extra credit.

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 opens with a specific verb+resource and a scope qualifier: activities that have signup configuration, explicitly including COMPETITION. This distinguishes it from the broad sibling list_activities, which lists activities without the signup-config constraint, so an agent can pick correctly without opening either schema.

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?

It gives an explicit downstream workflow (slug → get_signup_activity → submit_signup) and names the alternative for the multi-session case (get_signup_gaps). It also states the when-not condition for re-applying ('submitted勿重复报') and the fallback when q returns empty results.

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