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

The readOnlyHint=true annotation already tells the agent this is a safe read. The description adds the underlying API mapping (GET /lab_tests/{id}), which is marginally useful for tracing but does not disclose return shape, error behavior on a missing id, or the effect of the optional age/model_id/dev_mode context.

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 terse sentences with the purpose front-loaded and zero filler. Every phrase carries information (the id scoping and the endpoint mapping).

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 read-only fetch with full schema coverage, so the core is adequate. With no output schema and no description of the returned lab test object, an agent gets no sense of what fields come back or how the optional age/model_id parameters alter the response.

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 all four parameters (id, age, dev_mode, model_id) are already documented in the schema, including the enum and header mappings. The description adds no parameter-level information beyond that, so 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 ('Get a single lab test by its id'), and the word 'single' distinguishes it from the sibling infermedica_list_lab_tests. It does not name that sibling explicitly, so the differentiation is implied rather than stated.

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 id' phrasing implies usage when a lab test id is already known, which is the natural contrast with a list/search tool. However, no explicit when-to-use, when-not-to-use, or named alternative is given.

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