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

Beyond the annotations (read-only, idempotent, open-world), the description adds critical behavioral details: the two pipeline paths (SEC EDGAR/XBRL vs. grounded), the exact verdict list, the meaning of 'could_not_verify' (not evidence) vs. 'unsupported', and the citation format. This is extensive and highly valuable context not inferable from 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?

Though lengthy, every sentence serves a purpose: trigger phrases, usage guidance, pipeline explanation, return value specification, and crucial caveats. The structure is front-loaded and logically ordered, with no fluff or redundancy.

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 must explain return values and does so thoroughly, including all verdicts, the actual value with citation, reasoning, and error semantics. It also covers the two distinct execution paths and the efficiency benefit, making the description self-sufficient for a tool of this complexity.

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 both parameters (claim and tolerance_pct) already fully described in the input schema. The description does not add significant parameter-level meaning beyond what the schema provides, so it stays at the baseline of 3.

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's purpose: natural-language claim verification against authoritative sources. It includes trigger phrases and specific verb+resource framing ('verify the claim that…'). It differentiates from sibling tools by focusing on fact-checking with structured verdicts and by mentioning it replaces 4–6 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?

The description provides explicit when-to-use guidance: 'Use whenever the agent needs to check whether something a user said is factually correct.' It also explains the routing for company-financial vs. other claims. However, it does not explicitly list when-not-to-use or name alternative sibling tools, so it falls short of a 5.

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