search_companies_by_locality

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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the safety bar is largely covered. The description adds one real behavioral fact: matching is by registered seat rather than street address, which can differ from operating premises. It says nothing about result volume, pagination, or what happens when the locality string is ambiguous.

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?

Two short sentences, scoping constraint first, with zero filler. The second sentence is a fragment but reads as a deliberate usage caveat rather than noise.

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 three-parameter search tool with no output schema, an agent still lacks any sense of what a result record contains or how many/which fields are returned. The core selection information is present, so it is adequate but not complete.

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 67%; name and locality are documented in the schema while limit is not. The description reinforces that locality means a commune/town rather than a street, but adds no format, matching, or limit behavior beyond what the schema already says. 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?

Names the resource (companies) and the exact filter semantics (registered seat in a commune/town), which is a meaningful distinction from a name or address search. It stops short of a full verb phrase and never mentions the sibling search_companies by name, so differentiation is implied rather than explicit.

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?

Usage is implied: call this when the only known attribute is a locality. The note 'ZEFIX has no street-address search' usefully tells the agent not to attempt address lookups, but there is no statement of when to prefer search_companies or get_company instead.

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