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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, establishing this as a safe lookup. The description adds meaningful context: it returns a ranked shortlist, mirrors the 'Get Matched' tool's logic, and implies matching ranking behavior. No contradiction with annotations.

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 core behavior is front-loaded, followed by a clear WHEN TO USE block and explicit sibling routing. Every sentence contributes to selection or invocation, and there is no fluff or redundant restating of the 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 read-only matching endpoint with a fully documented schema and no output schema, this description is complete. It states the expected input, what is returned (a short ranked shortlist), required minimum input (one service), and how to navigate to alternatives. Nothing needed for correct invocation 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 description coverage is 100%, so the schema already defines every parameter including constraints like minItems for services and budget ranking behavior. The description only paraphrases the general buyer brief fields (services, location, budget, industry) without adding new semantic value, which matches the baseline.

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?

Clearly states the verb and resource: 'Agency's matching engine' that 'returns a short ranked shortlist of agencies' from a buyer brief. It distinguishes itself from siblings by explicitly naming search_agencies and get_agency and when each is appropriate.

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 when-to-use guidance: when the user describes needs and wants a recommendation, and requires at least one service. It also names alternatives: use search_agencies for open browsing/filtering without a brief rentrant, and get_agency to drill into a result afterwards.

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