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

The description goes beyond annotations by explaining the two internal routing paths (SEC EDGAR fast path vs. grounded pipeline), the exact verdict list, and the critical distinction between could_not_verify and unsupported. It also warns that could_not_verify must not be treated as evidence, which is valuable behavioral 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 front-loaded with trigger phrases, then states the core purpose, followed by detailed routing and return semantics, and ends with an efficiency note. Every sentence provides necessary information for an agent to select and invoke the tool correctly, with no wasted words.

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 that there is no output schema, the description thoroughly explains the return value (verdict, actual value, citation, reasoning), edge-case verdicts, and error semantics. It also covers the two major claim categories, making it complete 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?

Although the schema already provides full descriptions for both parameters, the tool description adds semantic context by explaining how the claim's domain (financial vs. other) affects processing. The tolerance_pct is only covered by the schema, but the routing insight justifies a 4 rather than the baseline 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 uses a specific verb ('verify', 'fact check') with a clear resource ('natural-language claim verification against authoritative sources') and includes example trigger phrases. It distinguishes itself from siblings by focusing on fact-checking claims with a special path for company-financial data.

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?

It explicitly states when to use the tool ('Use whenever the agent needs to check whether something a user said is factually correct') and notes that it replaces 4–6 sequential calls. However, it does not explicitly name alternative tools or conditions when not to use it, 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.