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

Annotations already declare readOnlyHint=true, so safety is covered. The description adds genuine behavioral value the annotations do not supply: the underlying FHIR call shape and the return contract ('FHIR searchset Bundle'), letting the agent plan for the response envelope.

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 terse sentences, front-loaded with the action and immediately followed by the endpoint and return type. Nothing redundant or padded.

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 tool with no output schema, the description supplies the two things missing from structured fields: the FHIR endpoint and the Bundle return shape. Only broader routing guidance (vs. get_patient_everything) is absent.

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 coverage is 100% with a single documented patient_id, so the schema carries the parameter meaning entirely. The description's 'patient={id}' restates the schema without adding format or lookup semantics, so 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 it to a concrete endpoint. It is clearly distinguishable from the list_allergies/list_conditions siblings, though it does not explicitly address overlap with healthgorilla_get_patient_everything, which may also surface coverage.

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?

No when-to-use or when-not-to-use guidance, no prerequisites, and no mention of alternatives for retrieving coverage data. The agent must infer that this is the right call whenever coverage is needed.

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