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

Annotations already declare readOnly/idempotent/non-destructive/openWorld=false, so the safety profile is covered. The description adds genuinely new behavioral context: slot labels are 2-hour windows whose start is the arrival time, and resolvedLocation reports how the place was interpreted. That is real added value 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?

Front-loaded with the purpose, then slot-label semantics, then location-resolution guidance. Three sentences, each doing work, with no filler; slightly dense but well ordered.

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?

With no output schema, the description carries the return-value burden and does so: it names remaining capacity, expected busyness, and resolvedLocation. The only untreated gap is pagination or result-count behavior, which is minor for this query tool.

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%, so the baseline is 3. The description goes further by explaining how the location parameter is resolved and how a returned slot label should be interpreted temporally, adding meaning the schema does not carry.

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+resource ('Open car-wash time slots near a place on a given day') and even specifies the granularity of the response ('for each centre, its slots with remaining capacity and expected busyness'). It is unambiguous what the tool does, though it never names a sibling to differentiate from find_centers or recommend_wash.

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?

Usage is implied by the scoping ('near a place on a given day') and there is a useful input-quality hint ('a concrete place resolves better than a vague area such as « Paris ouest »'). However, it gives no when-to-use versus find_centers or recommend_wash routing guidance, so it stops at implied usage.

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