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

Annotations already declare readOnlyHint=true, and the description aligns by saying 'Fetch' and 'GET /patients/{id}'. It does not add deeper behavioral context such as 404 handling or return format, but given the simplicity of the operation and the annotation coverage, a neutral score is appropriate. No contradiction exists.

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?

The description is one short sentence plus the endpoint, with no filler or redundancy. The key scoping information ('single patient by id') is front-loaded and every word earns its place.

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 simple read-only lookup with one required parameter, no output schema, and no nested objects, the description and annotations are sufficient for an agent to invoke it correctly and understand what it returns. The return value is adequately implied by 'Fetch a single patient'.

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?

The schema has 100% description coverage with 'Patient id.' for the single parameter. The description adds that the id is the path segment in 'GET /patients/{id}', which is mildly useful, but the schema already carries the parameter semantics, so the baseline score of 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?

The description states a specific verb ('Fetch') and resource ('a single patient by id'), which clearly distinguishes it from list_patients and other get_* sibling tools targeting different resources. Including the exact endpoint 'GET /patients/{id}' further reinforces its purpose.

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 clearly implies this tool is for retrieving one existing patient by its id, and the sibling names help differentiate it from listing/search tools. However, it does not explicitly state when not to use it or name an alternative, so it stops short of full usage guidance.

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