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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds the context that it returns per-source status and a full rate breakdown, and that it is diagnostic, which is useful but not essential given the output schema carries return details.

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: a precise function statement, concrete use-case triggers, and an exclusionary closing note. There is no filler or repetition of schema content.

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 a high-coverage schema and an output schema present, the description provides enough additional context: when to call it, example questions, and the distinction from casual recommendations. Nothing critical is missing for an agent to select and invoke this tool 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 coverage is 100%, so every parameter is already documented in the input schema. The description reinforces the notion of per-supplier statuses but does not add meaning beyond what the schema provides, which matches the baseline score of 3.

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 opens with a specific verb and resource — 'Diagnose rate availability and per-supplier statuses for a specific hotel' — and grounds it in concrete user questions like 'why is there no AAA rate?'. It clearly distinguishes itself from sibling tools by stating it is diagnostic and not for casual recommendations.

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?

It provides an explicit when-to-use trigger: when a power user asks why certain rates aren't showing, with two concrete examples. It also excludes casual recommendation use, but it does not name specific alternative tools to use instead, so it falls just short of a 5.

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