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

Annotations declare readOnlyHint=true, so the agent knows it's a safe read operation. The description adds valuable behavioral context beyond annotations: it compares against local medians computed from a private directory, returns a coverage figure because the public tier can only see part of the audit, and warns never to present the score as a complete audit. This is exactly the kind of context that helps an agent set expectations and avoid misusing the result.

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 description is three sentences, each earning its place: the first states the core function, the second explains the comparison methodology, and the third discloses the coverage limitation. It is front-loaded with the action and resource, and there is no wasted wording.

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 tool with two well-documented parameters and no output schema, the description is quite complete. It explains the scoring basis, the local median source, and the coverage limitation. The only minor gap is that it doesn't describe the exact return format (e.g., whether the ranked missing items are a list or a string), but the description's warning about coverage is more important and is covered.

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 documents both parameters. The description adds context about the business types and the comparison logic, but it doesn't add much detail about the parameters themselves beyond what the schema provides. Baseline 3 is appropriate because the schema does the heavy lifting.

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 states a specific verb ('Score'), a specific resource ('a named barbershop, salon, barber/cosmetology school or beauty supply store's public Google Business Profile'), and the output ('what is missing, ranked'). It also distinguishes itself from siblings by naming the exact business types it covers, which helps an agent select it over compare_barbershops_salons or compare_barber_cosmetology_schools.

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 clearly implies when to use this tool: when a single named business needs a Google Business Profile score. It does not explicitly state when not to use it or name alternatives, but the sibling list and the description's focus on a single business make the usage context clear. A small gap: it doesn't explicitly say 'use compare_barbershops_salons for comparing multiple businesses'.

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