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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower; the description still adds real value by defining the four verdict labels and warning that NOT CHECKED never means false. That is exactly the misuse it needs to prevent. It stops short of describing the actual response payload or what the 'next step' field contains.

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 dense sentences, front-loaded with the action and immediately followed by the verdict taxonomy; no filler. The phrase 'with a next step' is cryptic and slightly undermines an otherwise tight statement.

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?

With only one parameter and a read-only, idempotent profile covered by annotations, the main remaining burden is return semantics, which the description handles by naming all four verdicts. Since no output schema exists, the description should also sketch the response shape and explain the 'next step', which it does not.

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% with a single documented 'text' parameter, so the baseline is 3. The description contributes one useful nuance — that the input may contain multiple claims to be found — but adds no format or length guidance beyond the schema's maxLength.

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 (find and check) and resource (claims), and bounds the scope precisely: arithmetic, primes, unit conversions. The boundary 'the ones plain code can' implicitly separates it from lookup_fact, but no sibling is named, so sibling differentiation is left to inference.

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 scope statement implies when to use it (computable claims only) and the OPEN/NOT CHECKED outcomes imply when it won't answer. However, it never says 'for factual/world knowledge use lookup_fact' or any other explicit routing, leaving the agent to infer the alternative.

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