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

Annotations only declare readOnlyHint=true; the description goes well beyond that by disclosing that the tool returns named status codes (profile_incomplete, organizer_profile_required, no_published_product) and what each implies. Crucially it discloses a capability boundary — that SMS verification cannot be completed through MCP — which an agent could not infer from any structured field.

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?

Extremely dense and front-loaded — the precondition list comes first, then the remediation branches in the order an agent would encounter them. The telegraphic, semicolon-chained Chinese style packs maximum information but is slightly harder to parse on first read than a structured list would be.

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 zero-parameter read-only gate with no output schema, the description covers everything an agent needs: the eligibility criteria it validates, the failure codes it emits, the remedy for each, and the follow-up tool. The only minor omission is the exact response shape, which is largely implied by the enumerated codes.

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 tool takes zero parameters, so there is nothing for the description to disambiguate and the schema-coverage baseline of 4 applies. No parameter text is needed or missing.

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?

"办活动先查" plus the enumerated preconditions (bio/intro ≥10 characters, published product, organizer onboarding fields) states a specific verb and resource rather than restating the name. It also positions itself relative to siblings: it is the gate before create_organizer_activity, with create_product as a prerequisite branch. An agent can distinguish this from create_organizer_activity 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?

Explicit sequencing instruction ("办活动先查" = check this first before launching an activity) and a routing table for each outcome: profile_incomplete → complete onboarding, no_published_product → create_product first, otherwise → create_organizer_activity. It even states a hard exclusion: organizer_profile_required requires App SMS verification and cannot be written via MCP.

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