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

The description does not disclose any behavioral traits beyond the annotations. It doesn't mention what happens after booking, error handling, side effects, or confirmation behavior. The annotations already indicate it's a write operation, but the description adds no operational context.

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?

The description is two sentences, front-loaded with the purpose and a concise prerequisite. No wasted words.

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 booking tool with 6 parameters and no output schema, the description is too brief. It omits key information about required parameters like serviceId, what constitutes a successful booking, and return value, leaving the agent to rely on schema and inference.

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 only 50%, and the description does not compensate for undocumented parameters. It repeats the 'slug' and 'startsAt from check_availability' hints from the schema but provides no meaning for serviceId, customerName, or note, which are left unexplained.

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 the tool books an appointment at any business by slug, using a specific verb and resource. It distinguishes from siblings like check_availability by directly referencing it and focusing on the booking action.

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 description gives explicit guidance to confirm the slot with check_availability first, which is clear usage context. However, it does not mention when not to use the tool or explicitly name alternatives, 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.