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

Adds real context beyond annotations: callback within the hour during business hours, free to the homeowner, consent requirement, and a return reference plus next steps. Annotations already cover the openWorld/non-idempotent/non-destructive profile, so the remaining gap is mainly that duplicate submissions aren't warned about.

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-loaded and appropriately short, but the parenthetical '(a vetted local pro calls back within the hour during business hours)' redundantly restates the preceding clause about the same pro calling back, wasting a sentence fragment.

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 7-parameter write tool with no output schema, the description covers what happens after submission (reference plus next steps), timing, cost, and the pre-check. It could still say what happens when the ZIP is out of area, but nothing an agent needs to invoke it 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 every field including zip, need, language and preferred_time is already documented. The description adds no format or constraint detail beyond mentioning the ZIP, so 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?

States a specific verb and resource ('Book radon mitigation'), plus the service area (Lexington) and the concrete outcome (a vetted local pro calls back). This is clearly distinguishable from check_service_area, which it explicitly routes to for ZIP validation.

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 precondition and alternative: only for a real person who asked, with consent, and 'Check the ZIP with check_service_area first if unsure.' Clear context and a named sibling, though it never mentions get_service_info or states outright when not to use this tool beyond the consent constraint.

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