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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds genuinely new behavioral context: the times are Brasília time, each result carries a booking_url pre-selecting day and time, the human confirms externally with name/e-mail/WhatsApp, and nothing is booked by this call. That is exactly the kind of side-effect clarification an agent needs.

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 sentences, front-loaded with the purpose followed by the booking mechanics; every clause carries information (timezone, URL behavior, confirmation path, no-booking guarantee). Slightly dense but not padded.

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?

There is no output schema, so the description must explain the return shape, and it does: a list of open times plus a booking_url per time. Combined with the annotation-backed safety profile, an agent has everything needed to call and interpret this 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% and both parameters are described there, including the enum meanings, so the schema carries the load and a 3 baseline applies. The description restates the type semantics but says nothing about the 'from' date parameter (format, default behavior).

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 gives a specific verb+resource ('find open times') and scopes it to two clearly differentiated purposes, explaining the Portuguese enum values in plain language. Nothing about it could be confused with the sibling tools (list_plans, search_help, read_help_article).

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 clearly explains when to pick each type value ('apresentacao' for clinics evaluating the system, 'treinamento' for clinics already using it) and flags that booking is not done here, implying a separate confirmation step. It does not name an alternative tool or state explicit when-not-to-use conditions, so it falls short of a 5.

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