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

Beyond the readOnlyHint annotation, the description reveals that the tool performs a multi-step operation: fetching the API home then following the fx:store link via GET. This explains the underlying HTTP calls and the indirection involved, which is useful behavioral context not present in the schema or 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?

Three concise sentences with no filler. The main action is front-loaded, followed by practical usage guidance and the underlying HTTP route. Every sentence earns its place.

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 zero-parameter, read-only discovery tool, this description is complete. It explains what the tool returns, why an agent would call it, and how the resolution works internally, so an agent can invoke it correctly without additional context.

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 tool has zero parameters and the schema is fully covered, so schema-level semantics are trivially complete. The description adds value by explaining what the result contains (the default store and its id) and how that result should be used.

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 action ('Resolve and return the authenticated user's default store (and its id)') and names the resource. It clearly distinguishes itself from sibling tools like foxy_get_api_home and foxy_get_store by focusing on the default store rather than any arbitrary store.

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 says to use this tool to discover the store_id that list tools accept, giving clear actionable context. It does not explicitly state when not to use alternatives like foxy_get_store or foxy_get_api_home, but the intended role before list operations is clear.

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