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

Annotations only declare readOnlyHint=true, and the description stays consistent with that. It adds real behavioral context beyond the annotation: results contain no contact information, expiresAt marks genuine expiry, and the agent must not invent other urgency cues.

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 short and front-loads the login prerequisite and result scope before the follow-up routing. The semicolon-telegraphic style is dense but each clause carries information; a slightly more structured phrasing would read better.

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 read-only, parameter-free list tool with no output schema, the description covers scope, data exposure (no contact info), follow-up tools, and expiry semantics. That is sufficient for an agent to call it correctly, with only sibling differentiation left implicit.

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 no parameter semantics to explain; the baseline for a param-free schema applies. The description correctly adds no parameter detail because none is needed.

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 states a specific verb and resource: it returns pending-response and recently-responded activity invitations, and notes that no contact info is included. It is clearly more specific than a bare name restatement, though it does not explicitly contrast with near siblings such as get_my_invite or list_my_organization_invites.

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?

It gives concrete routing: respond via respond_activity_invitation according to the user's own decision, and when profileNeeded=true, use get_my_guest_profile/update_my_guest_profile. This tells the agent what to do next and which sibling handles the follow-up action, though it does not state when NOT to use this list.

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