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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds substantial behavioral context beyond that: the automated routing logic, the distinction between 'could_not_verify' (check did not happen) and 'unsupported' (no source found), the error structure, and the claim that it replaces 4–6 sequential calls. No contradiction with annotations.

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 long but every sentence earns its place. It opens with concrete invocation examples, then states the use case, then explains behavior, return values, and edge cases. It is information-dense without redundancy, and the structure naturally leads the reader from what and when to how and what to expect.

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 and lack of an output schema, the description is exceptionally complete. It covers the entire pipeline, return verdicts with meanings, error handling (could_not_verify vs unsupported), and the fact that it consolidates multiple steps. The annotations and full schema coverage further round out the picture, leaving no critical 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 description coverage is 100% (both 'claim' and 'tolerance_pct' have thorough descriptions, including examples and default behavior). The tool description itself does not add parameter-specific meaning beyond what the schema provides, so the baseline 3 is appropriate.

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 identifies the tool as natural-language claim verification against authoritative sources, with specific verbs ('verify', 'fact check') and a well-defined scope. It also distinguishes between company-financial claims (via SEC EDGAR/XBRL) and other factual claims (via grounded pipeline), which helps differentiate it from siblings like deep_research or compare_entities.

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 explicitly states 'Use whenever the agent needs to check whether something a user said is factually correct' and clarifies the two sub-paths (financial vs. other claims). However, it does not explicitly name alternative tools or state when not to use this tool, so it stops short of full when/when-not guidance.

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