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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false and openWorldHint=false, so the mutation profile is covered. The description adds beyond that: it returns a link, and the agent is told to surface unavailable-in-city and incompatible tests from the response, which is real post-call behavior. It stops short of noting link lifetime, idempotency implications, or retry behavior, so not 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 short sentences, front-loaded with the core operation, then the trigger condition, then the prerequisite and post-call duty. No sentence is 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?

An output schema exists, so return values needn't be described in full, yet the description still tells the agent what to do with response content (report unavailable/incompatible tests). Combined with the trigger and prerequisite, an agent has everything needed to call this correctly.

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%; both parameters are documented with their source tools (lab4u_tests_search, lab4u_cities). The description repeats the 1-20 cap that maxItems/minItems already encode and adds no further format or edge-case detail, 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 (assembles a cart from a list of test IDs), names the scope limit (up to 20), the city dependency, and the return value (a link). The purpose is distinguishable from siblings like lab4u_basket_check without opening any schema.

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?

Explicitly says when to call ("when the user has agreed to the list") and names an alternative plus its triggering condition (check via lab4u_basket_check first if the user had a specific list). Both the positive and the prerequisite case are spelled out.

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