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

Annotations already mark readOnlyHint=true, so no safety caveat is needed. The description adds meaningful behavioral context: booth rent is 'quoted directly by shops rather than scraped,' coverage is partial, and the response states how many listings publish a rate. This is valuable provenance and trust information beyond what annotations provide.

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?

Three sentences, each earning its place: the purpose, the practical answer it provides, and the critical coverage caveat. The description is front-loaded with the core ranking criteria and contains no filler.

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 search tool with six self-describing parameters and no output schema, this is largely complete: it explains scope, ranking dimension, availability filters, and the partial-coverage caveat. It does not describe the exact response shape, but the schema and read-only annotations cover enough for an agent to invoke it correctly.

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 description need not repeat parameter definitions. It does add useful framing such as 'weekly' booth rent and the city-level chair availability interpretation, but it does not meaningfully expand on individual parameter formats beyond what the schema already says.

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?

The description names a specific verb and resource: 'Find barbershops and salons ranked by weekly booth rent' and states the axes (chairs available, Google rating, review count, hiring status). This clearly distinguishes it from a sibling like compare_barber_cosmetology_schools and signals it is a list-level comparison rather than a single-entry lookup.

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?

The description provides useful usage context: it 'answers what a chair costs in a given city and which shops have one free,' implying a city-scoped search. However, it does not explicitly say when to prefer this tool over booth_rent_for_city or give any exclusions, so sibling differentiation is left to inference.

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