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

Annotations declare readOnlyHint=true, and the description aligns with a read-only 'Describe' action. The description adds minimal behavioral context beyond the annotation, such as the specific aspects covered (service, price, inspection checks). No contradictions, but no additional safety or permission 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?

A single, direct sentence that conveys the tool's purpose without extraneous words. It is well-structured and front-loaded.

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 tool with no parameters and no output schema, the description provides adequate context, listing key aspects of the service. However, terms like 'Merchant Context service' and 'inspection checks' could be further clarified, so a 4 rather than 5.

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?

The input schema is empty with 0 parameters, so schema coverage is effectively 100%. The description doesn't need to explain parameters, and the baseline for 0 params is 4.

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 uses 'Describe' as a specific verb targeting the Merchant Context service, explicitly listing service, price, and inspection checks. This clearly states the tool's function, though it doesn't differentiate from sibling tools like check_merchant or inspect_merchant, so not a 5.

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 no guidance on when to use this tool versus sibling tools. It neither mentions alternatives nor specifies scenarios, leaving the agent without usage context. This warrants a low score.

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