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

Annotations already declare read-only, idempotent, open-world behavior, and the description goes beyond them by disclosing jurisdiction-dependent field completeness, pre-payment rejection of unsupported requests, and the exact price and payment rail (x402 on Base mainnet). That billing behavior is not derivable from any structured field.

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?

Four compact sentences, front-loaded with the core action, followed by coverage caveats and pricing. Every sentence carries information; no filler or repetition of the tool name.

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?

Output schema exists, so return values need no explanation, and the definition covers the remaining agent-relevant unknowns: data coverage, jurisdictional variability, failure behavior, and cost. Only the entity-vs-company sibling relationship is missing.

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% and the parameter description already says the ID comes from search_company and must be passed unchanged. The body only restates 'using its stable CelerAPI entity ID', adding no new syntax or format guidance, so the baseline 3 applies.

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?

States a specific verb and resource ('Retrieve normalized authoritative profile information for a resolved legal entity') and the identifier it keys on (stable CelerAPI entity ID). It does not explicitly distinguish itself from the sibling get_company_profile, so the entity-vs-company split must be inferred from the name.

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?

Adds useful usage boundaries: coverage is limited to GB and NO, and unsupported capabilities are rejected before payment, which tells the agent when a call will fail. It never states when to prefer this over get_company_profile or the entity_* siblings, so sibling routing is left implicit.

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