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

Annotations already establish it is a safe, idempotent read; the description adds substantial context beyond them: busy_count is informational because no per-slot cap exists, a reservation is a request the restaurant confirms, and the tool is public with no auth.

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?

Front-loaded with the core capability before the caveats, and the guest-messaging rule is well placed. Slight redundancy: 'busy_count ... is informational' is stated twice, and the mid-sentence 'A reservation is a REQUEST' interrupts the slot/return-value flow.

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 carries the burden and explains the one non-obvious returned field (busy_count) and the request-not-confirmation model. It omits any mention of other slot fields or result size, which is a minor gap for a 2-param read 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 0%, so the description must compensate and it largely does: 'days' is bounded to 1-7 and 'restaurant' is constrained to a listed venue with a reservation module, plus slot duration and timezone semantics. It stops short of describing accepted restaurant identifier formats.

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 precise verb+resource (list bookable reservation slots), with granularity (30-minute), horizon (next 1-7 days) and timezone. The scoping phrase 'for a listed restaurant with a reservation module' distinguishes it from siblings like request_reservation and reservation_summary.

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 clear context for use (a listed restaurant that has a reservation module) and adds an important behavioral rule about how to communicate results to guests, distinguishing slot lookup from an actual booking. It does not explicitly name request_reservation as the follow-up action, so routing is implied rather than stated.

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