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

The readOnlyHint annotation already covers the safety profile, and the description adds useful behavioral context by disclosing the HAL collection response shape and the exact GET endpoint. It does not contradict the annotation and provides value beyond the structured metadata.

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 short sentences, each earning its place: purpose, return format, and API endpoint. It is front-loaded with the core action and contains no filler or redundant restatement of the title.

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 simple read-only list operation with no required parameters, the description covers purpose, response representation, and endpoint. Pagination and default store behavior are already documented in the schema, so the definition is largely complete, though it could briefly mention when filtering by email or pagination is relevant.

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 four parameters are already fully documented in the input schema. The description adds no additional parameter-level meaning beyond what the schema and endpoint path convey, 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 states a specific verb and resource: 'List a store's customers,' and notes it returns a HAL collection embedding fx:customers. It is clear, but it does not explicitly differentiate itself from the sibling foxy_get_customer beyond the plural resource and collection format.

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 alternatives such as foxy_get_customer or foxy_update_customer. There are no exclusions, prerequisites, or routing conditions, leaving the agent to infer usage from the tool name and siblings.

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