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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds valuable context beyond that: '(metadata only)' tells the agent no binary image content is returned, and the underlying 'GET /live_photos?applicant_id=…' endpoint discloses the real API call and query shape.

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?

Two short sentences, front-loaded with the operation and scope, with the API path as a compact second sentence. No filler; every clause contributes.

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-only list tool with no output schema and annotations covering safety, the description is nearly sufficient, and '(metadata only)' usefully hints at the return shape. It falls just short on sibling differentiation and pagination/return-detail expectations.

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 applicant_id is already fully documented in the schema as the required identifier. The description only restates it in the endpoint template and adds no format, syntax, or constraint details beyond what the schema provides, so the baseline 3 applies.

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 (live photos) scoped to a single applicant, and the '(metadata only)' qualifier narrows the payload. However, it does not distinguish itself from the very similar sibling onfido_list_live_videos, which an agent choosing between the two would need.

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?

There is no explicit when-to-use or when-not-to-use guidance and no mention of alternatives. Given the near-identical sibling onfido_list_live_videos, the absence of routing guidance is a real gap, leaving the agent to infer selection from the name alone.

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