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

Beyond the read-only/idempotent annotations, the description discloses critical behavior: the distinction between 'could_not_verify' (check did not happen) and 'unsupported' (no source exists), instructing callers not to treat 'could_not_verify' as evidence. It also explains the dual pipeline and returns verdicts with citations, adding substantial context.

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 serves a purpose: trigger phrases, core purpose, routing details, output summary, and a critical caller warning. It is front-loaded with the most important information and structured logically.

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 no output schema, the description fully compensates by explaining the verdict options, the meaning of error states, and the fallback mechanism. It also mentions the advantage of replacing multiple sequential calls, making the tool's behavior and expected results clear.

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?

The schema already provides detailed descriptions of both parameters, so the baseline is 3. The description itself doesn't add new parameter-level semantics beyond what the schema says, but it does give an example of a claim and reinforces the tolerance behavior indirectly.

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 a natural-language claim verification tool, with a specific verb ('verify') and resource ('factual claim'). It distinguishes itself from general Q&A siblings by focusing on fact-checking with a verdict outcome, and even separates company-financial vs. other claims.

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 states when to use: whenever the agent needs to check whether something a user said is factually correct. It also explains the routing behavior (SEC EDGAR fast path vs. grounded pipeline). It doesn't name alternative tools or exclusions, but provides clear context for appropriate use.

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