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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds 'free' and 'diagnostic' but does not disclose what the diagnostic entails, potential external requests, or return behavior, offering limited extra context beyond annotations.

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?

Two short sentences efficiently convey purpose and usage guidance with no redundant words. Front-loaded with the primary action, making it easy to parse.

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?

The tool has only one parameter, simple annotations, and no output schema, so the description is mostly adequate. However, it does not explain what the diagnostic returns or what 'diagnostic' covers, which could leave the agent guessing about result usage.

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% and the parameter merchant_url already has a clear description ('Public HTTPS merchant URL to check'). The tool description adds no additional semantics beyond the schema, so the baseline of 3 is appropriate.

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 clearly states the tool runs a merchant-site diagnostic, which is a specific verb+resource. It distinguishes from siblings like compare_offers and search_merchants, but overlaps somewhat with inspect_merchant without explicit differentiation.

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 explicitly instructs agents to use resolve_merchant before relying on merchant facts or actions, providing a clear prerequisite and context. It does not exclude alternatives or state when not to use, but the guidance is actionable.

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