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

Annotations already cover the read-only/idempotent/non-destructive profile, and the description adds substantial behavior beyond them: the downstream consent flow (submit_signup with agreement={versionId,accept:true}), the signing snapshot and organization audit trail, the hard rule never to check the box on the user's behalf, and version-conflict re-confirmation. This is exactly the extra context the annotations cannot carry.

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?

Front-loaded with the fetch condition, then the downstream workflow and edge cases, packing a lot of value into one paragraph. It is a bit run-on with semicolon-chained clauses, which slightly hurts scannability, but there is very little filler.

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?

There is no output schema and only one parameter, but the description covers the calling condition, the null/no-agreement case, the consent workflow, the audit behavior, and the version-conflict and required=false edge cases. An agent has everything needed to call this correctly and hand off to submit_signup.

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?

Only one parameter (slug) exists with 100% schema description coverage, so the schema already documents it and the description adds no syntax or format detail. Baseline 3 is correct when the schema fully carries the parameter semantics.

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?

States a specific verb+resource: fetch the full text of an activity's signup agreement ('取全文'), clarifying that null means no agreement exists. It explicitly distinguishes itself from get_signup_activity (whose required/accepted state gates the call) and submit_signup (which consumes the consent), so an agent can place it correctly without opening any 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?

Gives explicit when-to-use conditions ('get_signup_activity协议required且未accepted或activity_agreement_required') and an explicit when-not ('required=false已签/已报名无需重签'), naming the sibling that produces those states. Both the trigger and the exclusion are stated, leaving nothing to inference.

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