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

Annotations only declare readOnlyHint and openWorldHint; the description goes well beyond them by disclosing what is NOT returned (no price, fee or coverage), why (the affiliate handles pricing on the phone), and the licensing relationship ('Sigo Seguros is a licensed insurance agency, not an insurance carrier'). That sets agent expectations in a way the annotations cannot.

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-loads what the tool returns and the slug handoff, then the usage rule, then the return-value disclaimer. Every sentence carries information, though the two-paragraph structure is slightly longer than strictly needed for a one-parameter lookup.

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?

An output schema exists, so return values need no explanation, and the description still adds the useful negative disclosure about pricing and coverage. For a single-enum-parameter read tool, nothing an agent needs to call 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?

Schema description coverage is 100% and the single locale parameter is fully documented in the schema, including the enum and the instruction to derive it from the customer's own messages. The description adds no parameter-level detail, so the baseline of 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?

States the resource precisely ('the services that are live right now') and its role in the workflow ('with the slug to pass to request_service'), which cleanly separates it from the request_service sibling that consumes its output. An agent can identify what this returns and where it fits without opening any 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?

Gives an explicit directive ('Call it before asking the customer anything') plus the condition that makes it mandatory ('a service that is not in this list cannot be requested'). It also spells out the cost of skipping it, which is stronger than typical when-to-use guidance.

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