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

Annotations already declare readOnly, so the description adds valuable context: requires login, automatic expiry of invitations, and absence of contact information. This goes beyond annotation defaults and gives the agent insight into edge cases.

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?

Three clearly labeled sections (when to use, combination chain, data semantics) with no redundant phrasing. Every sentence serves a purpose, and the key trigger phrase is front-loaded.

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 tool, the description covers the trigger, the output scope, the workflow chain, and data caveats. No output schema exists, but the description implicitly states what is returned (invitations). Fully complete for an agent to call 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 has zero parameters, so the schema provides no semantics. The description fully compensates by explaining what the tool returns (pending + recent responded invitations) and its scope. This is complete for a parameterless tool.

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 clearly states it lists activity invitations (both pending and recently responded) with a specific trigger phrase. It differentiates from siblings like get_activity_invites by emphasizing the batch view and user-centric filtering.

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?

Explicitly states when to use (when user asks about being invited or unresponded invitations), and describes the added value over the App's individual tapping. No need for alternatives since this is a unique list tool.

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