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 genuinely useful context beyond the annotations with '(metadata only)', telling the agent that actual video content is not returned, plus the underlying endpoint. No pagination or rate-limit details, but the metadata clarification is a meaningful disclosure.

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 with zero waste: the resource and scope come first, and the API endpoint is a compact supporting detail. Nothing redundant or padded.

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 simple read-only list tool with one required parameter and no output schema, the description covers purpose, scope, and the metadata-only return characteristic. It could specify which metadata fields are returned or whether results are paginated, but it is close to complete for this tool's complexity.

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 is already documented as required in the schema. The description's URL template (GET /live_videos?applicant_id=…) reinforces how applicant_id is used but adds no format or syntax detail beyond the schema, 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 videos) scoped to an applicant, which cleanly separates it from sibling list tools like onfido_list_live_photos and onfido_list_documents. It stops short of explicitly naming those siblings, so sibling differentiation is implied rather than stated.

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?

Usage is implied by the resource name and the required applicant_id, but there is no explicit guidance on when to call this versus alternatives (e.g., list_live_photos, get_check) and no prerequisites or exclusions mentioned. Adequate but minimal.

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