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

readOnlyHint=true already establishes this is a safe read. The description adds the underlying API endpoint (GET /reports?check_id=…), which is useful for tracing behavior, but says nothing about pagination, ordering, result volume, or whether all report types are always present. Modest added value over the annotation.

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 tight sentences, purpose first, API hint second. Nothing redundant and nothing 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 single-param, read-only list tool with a fully documented schema, the description covers what is being listed and how. The only gaps are pagination/return-shape behavior, which are not covered by an output schema either.

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 check_id parameter is fully documented there, so the schema does the heavy lifting. The description's endpoint hint restates the same parameter without adding format, validation, or edge-case detail.

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 (reports) and immediately scopes it: 'the individual reports that make up a check', with examples (document, facial similarity, watchlist). This clearly distinguishes it from the singular sibling onfido_get_report and from onfido_list_checks.

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 phrase 'reports that make up a check' plus the required check_id imply you call this after obtaining a check id, but no explicit when-to-use or alternative is named (e.g. why this instead of onfido_get_report, or how it relates to onfido_get_check). Usage is inferable but not spelled out.

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