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

Annotations cover safety hints (idempotent, non-destructive, open-world), but the description adds real behavioral context beyond them: login is required, edits take effect immediately after confirmation, and moving the registration deadline forward invalidates already-started signup drafts, requiring impact confirmation. That side-effect disclosure is genuinely useful, though rate limits/response behavior are not covered.

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?

Highly compressed, front-loading the login requirement and the immediate-mutation warning, with bracketed sections separating the field constraints from the workflow chain. Every clause carries information, though the telegraphic style sacrifices some readability.

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 14-parameter mutation tool with annotations covering the safety profile and no output schema, the description supplies the missing operational context: auth requirement, side effects, immutable fields, and a verification call in the chain. A few parameters and the return behavior remain unspecified, keeping it slightly short of complete.

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 50%, so the description must carry extra weight; it clarifies the editable field families (title/description/time/images) and the immutable fields (slug/type), but leaves parameters like capacity, location, city, meetUrl, productId, and organizerName unexplained in both the schema and the description. Partial compensation only.

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 precise verb+resource ('改本人活动标题/正文/时间/图片') and explicitly names the fields that cannot be changed (slug/type) plus the nearby concern that the signup form is a separate call. This clearly separates it from siblings like update_activity_draft, update_activity_material, and update_organizer_signup_config.

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 a login precondition, a confirmation step, and an explicit workflow chain (list_my_activities取id→确认→update_activity→get_activity), and routes the registration-form edit elsewhere. It stops short of stating when NOT to use this tool (e.g., drafts), so not a full 5.

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