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

Annotations already state destructiveHint=false and idempotentHint=true, but the description adds genuinely new behavioral information: the existing confirmed time remains in force until a provider confirms a replacement. That tells the agent the call is a non-binding request, not an immediate mutation, which is exactly the kind of context annotations cannot convey.

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 short sentences with no filler, and the key fact about the standing appointment is stated up front. The terseness borders on under-specification rather than verbosity, but nothing is wasted.

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?

For a three-required-parameter mutation with no output schema, the description omits what happens after submission (pending state, whether the provider's confirmation arrives via appointment_status) and says nothing about the multi-window limit or timestamp format. The critical non-destructive semantics are covered, so it is adequate but with clear gaps.

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 67%; id and token are well documented in the schema as receipt/customer-link values. The undocumented `preferred` array is only obliquely addressed by "Request new windows," which doesn't convey that it takes 1-6 start/end window objects or the expected date format.

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 says "Request new windows," which gestures at proposing replacement time windows but never states the verb+resource as plainly as the name/title do; without the name, an agent could read "windows" as something other than time slots. The second sentence clarifies the reschedule semantics, which is the tool's real purpose, but only indirectly.

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?

There is no guidance on when to reschedule versus cancel_appointment, request_appointment, or counter_offer, and no prerequisites such as the appointment needing to be existing/confirmed. The only conditional information given is what happens to the old slot, which is behavior rather than usage routing.

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