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

Annotations already indicate read-only, open-world, idempotent, non-destructive. The description adds crucial behavior: how claims are routed, the exact verdict list, and the critical distinction between 'could_not_verify' (check failed, not evidence) and 'unsupported' (no source covered). It also discloses the 'verification_error{stage,detail}' payload, exceeding annotation coverage.

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?

The description is detailed but not bloated; every sentence adds necessary information. It is front-loaded with query examples and quickly moves to usage. It is longer than the ideal but the length is justified by the tool's complexity and the need to clarify ambiguous verdicts.

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?

Given the tool's complexity (routing, multiple verdicts, error semantics) and no output schema, the description covers the return value (verdict, actual value, citation, reasoning), explains edge cases, and clarifies the two failure modes. It is complete enough for safe invocation by an agent.

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% and both parameters are well-described, but the description adds further semantics: explains that tolerance_pct overrides the claim's implied tolerance, gives the default (implied by wording, capped at 5), and provides concrete example claims. This is valuable beyond the schema.

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?

The description clearly states the tool verifies natural-language factual claims, with specific verbs like 'fact check', 'verify', 'confirm or refute'. It distinguishes from sibling tools by explaining its scope (any factual claim) and its integrated pipeline that replaces multiple sequential calls.

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 says 'Use whenever the agent needs to check whether something a user said is factually correct', and distinguishes between company-financial claims (SEC EDGAR path) and other claims (grounded pipeline). However, it does not name specific alternative tools for when NOT to use it, so it stops short of a full 5.

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