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

Annotations already declare read-only, idempotent, and non-destructive behavior. The description adds valuable context beyond that: it states the tool never fabricates results, returns an honest 'not_found' with which sources were queried, and discloses cost and latency. This behavioral disclosure is not covered by 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 reasonably long but well-structured with clear headers (introduction, examples, when to use/not, cost, latency). It front-loads the core purpose and uses concrete examples that add value without excessive rambling.

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?

For a tool with only 3 simple parameters and no output schema, the description is exceptionally complete. It specifies the registries, return fields, not_found behavior, source transparency, cost, latency, and usage patterns. An agent has all necessary information to call it correctly.

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%, so the baseline is 3. The description adds little beyond the schema: it restates parameter purposes and provides usage examples, but does not offer deeper semantic detail (e.g., how to combine parameters, precedence rules). The examples illustrate but do not significantly enrich parameter understanding.

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 specifies the verb 'verify' and resource 'company record', and it details the exact registries queried and fields returned, making the purpose unambiguous. It does not explicitly differentiate from the sibling tool verify_business, though the focus on GLEIF/SEC and LEI distinguishes it implicitly.

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?

Includes dedicated 'WHEN TO USE' and 'WHEN NOT TO USE' sections with concrete scenarios (contract signing, vendor qualification) and exclusions (private companies, KYC). It does not name alternative tools, but the guidance is explicit and actionable.

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