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

readOnlyHint=true already declares this is a safe read, so the description's added value is the disclosure that the response is a FHIR searchset Bundle rather than a single Coverage resource — meaningful since no output schema exists. It still omits pagination, empty-result behavior, and auth requirements, so it adds context but not rich behavioral detail.

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 short sentences with zero redundancy, front-loaded with the human-readable purpose before the FHIR implementation detail. Every sentence carries information.

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 single-parameter read-only tool, the description covers purpose, endpoint, and return shape (searchset Bundle), which partly compensates for the absence of an output schema. Missing only pagination and result-count behavior to be fully complete.

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% and there is only one parameter (patient_id, documented as 'Patient resource id.'). The description's 'patient={id}' simply restates the schema, adding no format or source-of-id guidance, so the baseline 3 applies.

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?

States a specific verb and resource ('List a patient's insurance coverage') and pins the underlying FHIR operation (GET /Coverage?patient={id}), so the agent knows exactly what domain data is returned. It does not explicitly differentiate itself from siblings such as healthgorilla_fhir_search or healthgorilla_list_allergies, but the resource is inherently distinct enough to route correctly.

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 gives no when-to-use guidance, no prerequisites, and never mentions that healthgorilla_fhir_search could be an alternative way to query Coverage. The agent must infer usage purely from the resource name.

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