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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds value beyond that: the enablement precondition, the shape of the payload returned, and the underlying GET endpoint. It stops short of noting pagination or empty-result behavior.

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 compact sentences, front-loaded with the resource and its payload before the precondition and endpoint. No filler, no restatement of the title.

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 single-parameter read tool with no output schema, the description supplies the return fields, the precondition, and the endpoint — enough to call it correctly. Only pagination/empty-result behavior is unaddressed, which is a minor gap given the tool's simplicity.

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 100% and the single parameter event_id is fully documented in the schema with a pattern. The description adds no format, sourcing, or lookup hints for the id beyond the API path template, so the schema does the heavy lifting — baseline 3.

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 the resource concretely ('the people signed up for an event') and enumerates the returned fields (name, email, id), so an agent knows exactly what it gets. The verb 'list' comes from the tool name rather than the description, and no sibling is explicitly distinguished, but none of the 14 siblings covers signups, so confusion risk is low.

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?

Adds one genuinely useful precondition — 'Signups must be enabled on the event' — which tells the agent when the call will succeed. However, it gives no guidance on when to reach for this tool versus teamup_get_event or teamup_list_events, and no error behavior when signups are disabled.

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