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

Even though annotations already mark this as read-only, idempotent, and non-destructive, the description richly discloses behavioral details: the feed is pre-sorted (pinned → nearest deadline, with no-deadline last), returned kind counts are real server-side counts with empty categories omitted, each record carries a submitted=true/false flag when logged in, and startAtKnown=false marks an imported fallback date that should not be spoken to users. These are exactly the runtime behaviors an agent needs to know.

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 long but tightly organized into three labeled sections (when to use, chaining, caveats), with every sentence carrying actionable information. The most important decision—when to call it and what it returns for real signup flows—is front-loaded, and the numbered caveats are dense but non-redundant.

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 list endpoint with no output schema, the description is exceptionally complete: it covers trigger conditions, upstream/downstream tool chains, sort order, filtering semantics, pagination/limit implications, handling of missing dates, and the distinction from list_activities. An agent has concrete guidance on both invocation and interpretation of results.

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?

The input schema already documents all 5 parameters at 100% coverage, which sets the baseline at 3. The description adds meaningful extra semantics for q—it does not search description/track/award fields, and an empty q result does not mean the event is absent, so the agent should retry without q. It also warns that kinds narrow together with q and that the signed-up flag should prevent asking already-submitted users again.

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 this is the station's only list of genuinely signup-able opportunities, using a specific verb ('list') and resource ('signup feed'), and explicitly differentiates it from list_activities, which is the broader activity info feed. The opening example triggers ('recent signups / deadlines this week / hackathons') leave no ambiguity about what the tool does.

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 'when to use' section names concrete user intents that should trigger this tool, and the 'chain' section gives an explicit sequence: get slug → get_signup_activity(slug) → submit_signup(slug), or get_signup_gaps(slugs) for batch review. It also states when NOT to use it: external imported events belong in list_activities and must be signed up on the organizer's official site.

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