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

Annotations only declare it a safe, idempotent, closed-world read; the description adds the substantive caveats the annotations cannot: hours are published open/closed not live slots, candidate start times come from the staff schedule without subtracting existing bookings, and some may already be taken so they must be confirmed on the booking page. It also pins the response contract to GET /api/v1/availability?ref=.

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?

The negation of live availability and the routing to compare_options are front-loaded, and every clause carries information. The middle sentence is long and dense, stacking service matching, prices, durations, booking link and instructions into one run-on, which costs a little readability.

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 does the work of describing the returned fields: opening hours, matching offerings with prices and durations, booking link, step-by-step instructions, and candidate start times with their reliability caveat. Only the semantics of the time_after/time_before filters are left uncovered.

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 60% and the description adds meaning for ref (format source), date (opening hours on that date) and service (matching offerings). However, time_after and time_before are undocumented in both schema and description, so the description does not compensate for the coverage gap on those two filters.

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?

Opens with a specific verb+resource ('Published facts for one salon') and immediately negates the most likely misreading ('NOT live availability, NOT an extras-inclusive quote'). It names the sibling to use instead for decision-making, so an agent can separate it from compare_options without opening a 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?

Gives an explicit routing rule: use compare_options with salon=ref for service/budget/extras/date decisions, and use this tool for one salon plus a date. It also states the provenance of the ref ('from search_merchants'), which removes the main selection ambiguity.

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