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

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower. The description does add value by labeling the payload HEALTH DATA, flagging sensitivity that the annotation doesn't convey, but it says nothing about permissions, missing-record behavior, or response format.

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 sentences, zero filler, with the resource and scope stated first and the endpoint as supporting detail. Nothing here is redundant with the title alone.

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?

This is a simple one-parameter getter with no output schema, so the agent cannot learn what the returned record contains from anywhere. Minimal context is adequate for a read, but the absence of any return-shape hint leaves a real gap.

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 fully documented id parameter, so the schema carries the semantics and the baseline of 3 applies. The description adds no format or sourcing guidance beyond what is already structured.

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 ('Fetch a patient record by id') plus the underlying endpoint, which pins down exactly what is retrieved. It implicitly separates itself from halaxy_list_patients via the single-id scope, but never names that 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 description gives no when-to-use guidance and no alternatives; the only routing hint ('from the matching list tool') lives in the schema's parameter text, not the description. An agent must infer that this follows a list call to resolve an id.

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