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

Beyond the readOnlyHint annotation, the description discloses the HTTP endpoint (GET /) and the response nature: a home document containing _links/rels, including fx:store. This adds meaningful behavioral context about what the call returns without contradicting the annotation.

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 tight sentences with no filler. The core resource and key response detail come first, and the endpoint hint is placed at the end without waste.

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 no-parameter, read-only discovery call, the description is complete: it names the endpoint, identifies the response shape, highlights the most relevant relation, and states the use case. No essential invocation detail is missing, and the readOnlyHint covers the safety profile.

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?

There are zero parameters, so there is no parameter semantics burden. The schema coverage is 100% and the description adds relevant context about the endpoint, earning the baseline of 4 for a parameterless tool.

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 precisely states the resource (Foxy hAPI home document), the verb (GET), and the specific content (_links/rels including fx:store). This clearly differentiates it from sibling get/list tools by framing it as the HAL discovery entry point rather than a resource fetch.

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 gives a clear use case ('useful for HAL discovery') and notes the fx:store relation for the authenticated default store, which tells the agent when to reach for this tool. It does not explicitly contrast it with alternatives like foxy_get_default_store or foxy_get_store, but the discovery framing makes the usage context clear.

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