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

readOnlyHint=true already covers the safety profile, and the description reinforces it with '(non-mutating)' while adding genuinely new behavior: the return is an array of matches, and a 204 message is returned when nothing matches. It omits auth requirements, match-scoring behavior, and duplicate-handling consequences, keeping it short of a 5.

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 compact sentences, front-loaded with purpose, then return behavior, then the raw endpoint. Nothing is padded, though the bare endpoint URL adds little for an MCP caller and could be considered filler.

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?

With 13 parameters and no output schema, the description does carry some of the return-shape burden and discharges it by naming the array-of-patient-objects result and the empty-match case. It leaves unexplained how partial or ambiguous matches are resolved and whether results are paginated.

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%, so every one of the 13 parameters is already documented in the schema. The description adds only the collective notion of 'demographics' and no per-parameter syntax, format, or required-vs-optional nuance, 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 with scope: 'Search for an existing patient by demographics.' The demographic-search framing implicitly separates it from particle_get_patient (single-record retrieval), though no sibling is named explicitly, which is what a 5 would require.

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 tool for when it holds demographics but not an ID. There is no explicit when-to-use statement, no mention of particle_get_patient as the alternative, and no guidance on required data-sharing agreements or matching behavior.

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