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

Annotations already declare readOnly/openWorld/non-destructive, so the safety profile is covered. Beyond that, the description usefully discloses return ordering ('guest list order'), pagination mechanics ('pages hold up to 500 guests; pass next_cursor back as cursor'), and the auth requirement (Cotlet API key with app access) — real value-adds not derivable from structured fields.

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 resource and payload, then filtering, pagination and auth in separate sentences. Every sentence contributes; no filler. Slight redundancy between the first two sentences (both describe the returned fields) keeps it from a 5.

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 and 100% schema coverage on inputs, the description carries the return-shape burden and does so well: field contents, ordering, pagination, and the auth prerequisite are all present. Nothing an agent needs to call it correctly is missing.

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 coverage is 100%, so all six parameters are already documented, including the cursor's origin. The description restates the filter dimensions (RSVP status, tag, name) and the cursor round-trip, adding only marginal meaning over what the schema already says.

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 ('list') and resource ('guests') and enumerates the payload (party, plus-ones, tags, contact details, RSVP answers per question). An agent can distinguish it from joy_get_guest or joy_get_rsvp_summary by the plural collection scope, though the description never names those alternatives explicitly.

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 says you can 'filter by RSVP status, tag or name to narrow it down', which implies the when-to-use context, but gives no explicit guidance on when to call this vs joy_get_guest, joy_get_rsvp_summary, or the export siblings. Usage is inferable rather than stated.

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