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

Annotations already establish read-only, idempotent, non-open-world behavior, and the description adds useful behavioral context by spelling out what details are returned: availability, turnaround, weekend operation, gender restrictions, marker list, and preparation link. It does not discuss auth, rate limits, or edge cases such as unavailable tests, but it adds meaningful scope beyond the annotations.

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?

It is compact and front-loaded: the first sentence states what details are available, and the second states when to call it. Every clause adds useful scoping or trigger information without repetition.

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?

Given the tool's low complexity, full schema coverage, existing output schema, and annotations covering safety behavior, the description is complete enough to select and invoke the tool correctly. It explains the returned detail scope and usage trigger, while parameter provenance is handled in the schema.

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 both parameters are already documented: test_id from lab4u_tests_search and location_id from lab4u_cities. The description reinforces the city/test scope but does not add syntax, format, or selection guidance beyond what the schema provides, making the baseline 3 appropriate.

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 names a specific resource and scope: details about one test in a city, and enumerates the concrete attributes returned (availability, turnaround time, weekend operation, gender restrictions, included markers, preparation-rules link). This clearly separates it from the search/list sibling lab4u_tests_search, especially with the input schema noting test_id comes from that search tool.

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?

It gives an explicit trigger: call when the user asks about a specific test or needs to compare similar ones. It does not name when-not-to-use conditions or explicitly route broad search to lab4u_tests_search, but the usage context is clear.

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