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

The readOnlyHint annotation already establishes the safety profile, so the description mainly needs to add context. It does add that replies can be pulled in as a thread, but says nothing about authorization, missing-id behavior, or payload differences when full_thread is set beyond the schema's own phrasing.

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?

A single front-loaded sentence with no filler; the core operation comes first, followed by the id provenance and the optional thread mode. Every clause carries information an agent needs.

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 two-parameter read tool with readOnlyHint and no output schema, the definition covers what the tool does, where the id comes from, and the one optional behavior. It does not describe the returned object shape, which matters somewhat given there is no output schema, so it is not fully complete.

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 the baseline is 3, and the description earns one extra point by disclosing where review_id comes from (the id of a service or product element from feefo_list_reviews), which the schema does not say. It adds a small amount on full_thread ('full thread of replies') beyond the schema's 'Include replies and rating changes'.

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 and resource: 'Get one review by its id', which is clearly distinct from the sibling feefo_list_reviews. It also carries the scope distinction (one review vs. a list), though it doesn't name the other siblings it could be confused with, such as feefo_get_review_summary.

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?

Explicitly points to feefo_list_reviews as the source of the id, which is a real routing instruction an agent can act on. It also frames full_thread as an optional mode, but gives no guidance on when the summary or list tools are preferable, so it falls short of a 5.

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