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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The description adds genuine non-redundant context: it explicitly disclaims reservation and message sending, and notes that a supplied start is validated against the live schedule, which is the key behavioral detail 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 compact sentences, outputs front-loaded, and the negative scope constraint placed second where it belongs. No filler and nothing repeated from the schema or annotations.

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?

An output schema exists, so return values need no explanation, and all parameters are optional, lowering the cost of under-specification. What is delivered (what is prepared, what is not done, schedule validation) is sufficient for correct invocation, though the undocumented timezone parameter is a residual gap.

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 description coverage is 0% across three parameters, so the description carries the full burden. It hints at locale ('language') and start_at ('selected start') but gives no format, enum values, or effect for either, and timezone is not mentioned at all — half the parameters remain semantically opaque.

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 states a concrete verb ('Prepare') and enumerates the outputs (price, language, cancellation rules, official calendar link), which tells an agent exactly what this tool assembles. It is distinguishable from the sibling getters (get_available_slots, get_services_and_pricing) because it bundles them into a handoff, though it never says so explicitly.

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?

The clause 'Does not reserve a slot or send a message' usefully bounds the tool's scope and the note that an optional start is checked against the live schedule implies when to pass start_at. However, it never names an alternative tool or states the condition under which an agent should prefer this over get_available_slots or get_services_and_pricing, leaving routing to inference.

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