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

No annotations are provided, so the description carries the full burden. It usefully discloses the return shape (confidence score, matched terms, best excerpt) and, importantly, the underlying method (heuristic term-overlap, not semantic fact-checking), setting honest expectations. It does not disclose failure modes, error behavior, or rate limits.

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 tightly written sentences: the question first, then the return description and the crucial caveat. Every clause earns its place.

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-param verification tool without an output schema, the description covers purpose, return fields, and the heuristic caveat. It stops short of preconditions (URL must be fetchable) and error behavior, leaving minor gaps.

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 0%, so the two parameters (claim, source_url) are only named, not described. The description implies the argument shapes through its question but adds no format, length, or URL-validation detail. Baseline is low-context but the current text does not compensate for the coverage gap.

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 question the tool answers ('Does this source URL support a given claim?') and names the resource (source URL, claim). Distinguishable from siblings like fetch, check_link, check_change, which do not perform claim verification.

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 description clarifies the tool is heuristic term-overlap rather than semantic fact-checking, which implicitly guides against fact-check use. However, it never states when to use this tool versus fetching the URL directly or using the other sibling tools.

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