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

Annotations already declare readOnlyHint=true, openWorldHint=false, destructiveHint=false, so safety is covered. The description adds real behavioral value beyond that: the default search start (now) and the 7-day cap on the window, which constrain how results are produced.

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 tight sentences with no filler; the what-it-returns clause is front-loaded before the default-window behavior. Every clause carries information the agent can act on.

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 correctly specifies the return shape (ISO start_at plus local label), and it covers the default date behavior and window limit. It omits ordering/pagination details and doesn't state what an empty result means, but nothing blocking correct invocation is missing.

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, and the schema caps days at 7 and defaults date handling. The description adds meaning the schema does not: availability is 'with any technician' (no technician filter needed/possible) and an absent date defaults to searching from now.

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 start times for one service) and even describes the return shape (ISO start_at plus local label). It implicitly contrasts with book_appointment by being the read-only lookup, but it never names a sibling, so it falls short of a 5.

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 useful default context ('searches from now when no date is given; up to 7 days'), which tells the agent how to call it without a date. However, there is no explicit when-to-use/when-not guidance or pointer to book_appointment for the follow-up write, leaving the workflow relationship to inference.

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