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 genuinely useful return-behavior context — the payload may be a FHIR Binary JSON resource, XML C-CDA, or base64, and is returned as-is (raw text if not JSON) — which tells the agent how to parse the result.

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 tight sentences with the core action front-loaded and no filler. The middle FHIR-path sentence is mildly redundant given the name and title, but it usefully maps to the canonical API route.

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 one-parameter read tool with no output schema, the description covers the operation, the identifier source, and the possible response encodings. Minor omissions are error/not-found behavior, but nothing critical to correct invocation is missing.

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 the single binary_id parameter is documented in the schema as coming from a DocumentReference. The description adds no extra syntax or sourcing detail, 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 — 'Retrieve raw document content by Binary id' — plus the underlying FHIR endpoint GET /Binary/{id}. The 'by Binary id' scoping implicitly separates it from list tools like healthgorilla_list_documents, but no sibling is named explicitly.

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?

Usage is only implied: an agent can infer this is the follow-up call after discovering a Binary reference, but the description never states when to prefer this over healthgorilla_list_documents or healthgorilla_get_patient_everything, nor any prerequisites.

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