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

Annotations indicate a non-read-only, non-destructive write operation. The description confirms creation but does not add details like authorization needs, side effects, or rate limits. With annotations already covering the basic behavioral profile, the description adds the prerequisite step but little else.

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, no wasted words. First sentence states purpose, second provides critical usage guidance. Efficient and well-structured.

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?

Given the output schema exists (not shown, but indicated), the description doesn't need to cover return values. It covers purpose, prerequisite, and key parameters. With 8 parameters and moderate complexity, the description is adequate but could mention that the booking is created immediately or if any confirmation is needed.

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?

The input schema has 100% description coverage for all 8 parameters, so the schema already defines them well. The description mentions 'service, member, date, and time' which maps to key parameters but adds no new semantic meaning beyond the schema.

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 clearly states 'Create a new booking for a member,' specifying the verb and resource. It distinguishes from sibling create tools by adding the prerequisite step 'Use get_available_slots first,' making it clear this is specifically for bookings.

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?

Explicitly instructs the agent to first use get_available_slots to find valid times, then create the booking with the required parameters. This provides clear when-to-use and how-to-use guidance, differentiating it from other tools.

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