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

Annotations already declare readOnly, idempotent, open-world, non-destructive behavior, so the description's remaining job is narrower. It adds real value by disclosing the GB default, unsupported country codes returning errors, and the pay-per-call price of $0.0050 USDC via x402. It does not describe result volume, ranking, or what the response looks like, which is acceptable since an output schema exists.

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?

Front-loaded with the core action and scope, and every sentence is on-topic. However, it is a dense six-sentence block that mixes discovery guidance, jurisdiction coverage, legal disclaimers, and pricing; the disclaimer and price could be trimmed or separated to keep the selection sentence sharp.

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?

Covers what an agent needs before calling: jurisdiction support, default behavior, pricing, and the meaning of results as evidence rather than a compliance determination. With an output schema present, return-value detail is unnecessary, leaving only minor gaps such as result limits or ranking behavior.

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 all three parameters are already documented, including the GB default and supported codes. The description only restates and recommends country_hint rather than adding format or syntax detail beyond the schema, so the baseline 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 ("search authoritative company registries by company name") plus the outcome ("resolve candidate legal entities and registration identifiers"). It distinguishes itself from siblings like search_lei and search_sec_company by naming the registry type and the jurisdictions covered.

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?

Gives explicit routing guidance: "Use this first when the registration identifier is unknown," which tells the agent when this beats identifier-based lookups. It also sets the supported-country boundary, but never names a concrete alternative tool for users who already have an identifier or need SEC/LEI data.

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