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

Beyond the readOnlyHint annotation, the description discloses admin permission requirements, pagination via nextCursor, scope restrictions, contactAccess invitation semantics, and that phone numbers are not returned. This is substantial behavioral context for an agent.

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 dense but front-loaded: permission, scope rules, pagination, contactAccess mapping, and privacy note each appear in a compact sequence. Every clause carries operational meaning.

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 listing tool with an output schema absent, the description covers permissions, scope, pagination, contact-access interpretation, and a key privacy constraint. It is nearly complete, though it does not clarify the role of activityRef or describe the candidate result shape.

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 0%, so the description must carry the burden. It explains scope values, the public-search minimum length for q, and cursor pagination, adding real meaning beyond the raw schema; however, the required activityRef parameter is only implicit and not explicitly described.

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 title and name identify the resource (guest invitation candidates), and the description clarifies it is a scoped listing/search operation via scope values, pagination, and contactAccess semantics. It does not explicitly state a verb like 'list' or 'search', but the combined signals make the purpose clear and distinguish it from mutation siblings such as add_guest_candidates.

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?

The description gives explicit scope constraints: public search requires at least 2 characters, private activities must not use public scope, and contactAccess values determine whether/how candidates can be invited. It does not name alternative sibling tools, but the when-to-use and constraint guidance is strong.

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