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

readOnlyHint=true already declares this is a safe read, so the annotation carries the safety profile. The description adds only the endpoint path, and omits behavior an agent would care about for a lookup: what happens on an unknown id (404 vs empty), auth requirements, and response shape. Useful but thin beyond 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 short sentences, front-loaded with the action and identifier, then the endpoint. 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 one-parameter read with readOnlyHint covering safety and no output schema to explain, the description is nearly sufficient. A sentence on error behavior for an unknown id or on returned fields would close the remaining gap, but nothing essential 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?

Only one parameter, and the schema documents it fully (100% coverage) as the 'Particle-assigned patient id (from submit/search)', including provenance. The description's mention of the id adds no syntax or format detail beyond that, but with a single fully-described parameter the baseline is high.

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 (Fetch) and resource (a single patient record) scoped by the Particle patient id, and the inclusion of the REST endpoint makes the operation unambiguous. It differentiates implicitly from particle_search_patient (you must already hold the id) and from format-specific siblings like particle_get_fhir, but never names a sibling 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?

The 'by its Particle patient id' phrasing implies the precondition that an id is already in hand, which hints that particle_search_patient is the alternative when it is not. However, no explicit when-to-use, when-not-to-use, or alternative is stated, so the routing is left to inference.

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