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

Annotations already declare read-only/idempotent/non-destructive, so the safety profile is covered. The description adds real behavior: login required, results contain no contact info, and expiresAt governs expiration with a warning not to invent other urgency reasons — useful operational context beyond the annotations.

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 login requirement and scope, then routing, then expiry semantics. Dense but every clause carries information; no padding.

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?

With no output schema, the description picks up the slack by naming output-relevant fields (profileNeeded, expiresAt) and the absence of contact info. Combined with the annotations, an agent has enough to call and interpret 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?

The tool takes zero parameters, so per the baseline the schema fully defines the input surface. The description's references to profileNeeded and expiresAt clarify output semantics rather than inputs, which is a bonus not a gap.

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 (列出我收到的活动邀请) and narrows scope to pending plus recently responded invitations with no contact info. This distinguishes it from the many other invitation- and activity-list siblings, though it does not name a direct counterpart.

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?

Routes the agent explicitly: respond_activity_invitation is for acting on an invitation, and get_my_guest_profile/update_my_guest_profile are for when profileNeeded=true. Clear context is given, though no explicit when-not-to-use-this-tool exclusion.

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