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

With no annotations, the description carries the full behavioral burden. It discloses read-only behavior, the anonymised nature of results, that no tool returns names or contact details, and that an empty result is a real answer. It does not cover pagination, ordering, or response format, but the important boundary conditions are transparent.

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 front-loaded with the core purpose and read-only nature, then adds necessary caveats about anonymised data, empty results, and the get_matched alternative. Every sentence earns its place, including the agent-facing instruction about not implying partial results.

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?

Given the lack of an output schema, the description adequately lists the fields present in results and explains the no-match behavior. It also references the relevant sibling tool get_matched. It could additionally describe result ordering or size limits, but for this tool's complexity the description is largely 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 description coverage is 100%, so the schema already documents each parameter's allowed values and meaning. The description adds useful framing about optional filters and directory-wide behavior, but does not need to repeat parameter syntax. Baseline 3 is appropriate.

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: 'Filter the vetted agency listings by what they do and who they do it for.' The description also clarifies the data is anonymised and distinguishes behavior from get_matched, so an agent can tell what this tool is for.

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 every filter is optional and passing none returns the whole directory. It also explains what an empty result means and directs the agent to offer get_matched as the alternative, giving clear when-to-use and when-not-to-use guidance.

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