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

Annotations establish the safety profile (openWorldHint=true, idempotentHint=false, destructiveHint=false), and the description adds real operational context the annotations cannot: a vetted pro calls back within the hour during business hours, it is free to the homeowner, and it returns a reference plus next steps. It omits any warning that repeat calls create duplicate bookings, which is the main behavioral gap given idempotentHint=false.

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, but the callback timing is stated twice in a redundant parenthetical ('A vetted local pro calls them back (a vetted local pro calls back within the hour during business hours)'), which is pure duplication. The remaining sentences (consent, free, return, ZIP check) each earn their place.

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?

With no output schema, the description correctly summarizes the return ('a reference and what happens next'), and it covers consent, cost, callback timing, and the sibling pre-check — enough for an agent to invoke this 7-parameter booking tool correctly. Only the duplicate-submission behavior is left unaddressed.

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 every parameter (zip, name, phone, need, email, language) is already documented in the schema and the baseline of 3 applies. The description reinforces the ZIP check and the fact that the phone is the number the pro calls, but adds no format or constraint detail beyond the schema.

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+resource+scope: 'Book windshield replacement in the Tampa area', and immediately distinguishes itself from the sibling check_service_area by framing that tool as an optional pre-check. An agent can tell exactly what this tool does and how it differs from its siblings without opening a 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 gates usage on a real person having asked for it and given consent, and routes the agent to check_service_area first when the ZIP is unknown — a clear precondition plus named alternative. It stops short of a 5 because it never states when *not* to book (e.g., outside the service area or without a callback number).

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