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

Annotations already establish read-only, idempotent, open-world, and non-destructive behavior. The description adds crucial operational context beyond annotations: a 2-unit limit, the rule that only an official ID links exactly while a name plus address is never proof, and confirmation that nothing is stored.

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 purpose is front-loaded, then Inputs, Returns, and Limits are cleanly sectioned. Every part is brief and useful, with only minor overlap with the output schema.

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 7-parameter, open-world matching tool with a full output schema, the description covers country scope, input expectations, return shape, and limits. Nothing an agent needs to invoke it correctly 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?

With schema coverage at 71%, the description usefully groups and exemplifies the key inputs (country, name, postal_code, identifier, optional id_scheme, locality, limit) and clarifies the and/or relationship between name and identifier. It duplicates a few schema descriptions and leaves locality/id_scheme only lightly explained, so it adds value but not full compensation.

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 decision verb and resource: deciding whether a known company is in official registers, with evidence and candidate outcomes. It explicitly distinguishes itself from lookup_company, so an agent can select it without opening either schema.

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?

Explicitly says to use it for matching a supplier or customer record to a register record, and says not to use it to read a company already identified, directing to lookup_company. That gives clear when, when-not, and alternative.

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