Create a booking (approval required)

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

With no annotations, the description carries the full behavioral burden. It usefully discloses the authorization model (approval token bound to these exact arguments) and a uniqueness/side-effect implication ('free slot'), but says nothing about what happens on conflict, whether the approval is consumed, or how to undo the booking (cancel_booking exists but is not referenced).

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, zero filler, with the action front-loaded and the hard prerequisite escalated via capitalization so it cannot be skimmed past.

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 five-required-parameter mutation with a nested approval object, no annotations, and no output schema, the description covers the critical precondition but omits conflict/error behavior, whether booking creation is atomic with approval consumption, and any note on the returned booking identity.

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%, so the description must compensate. It does add real meaning for two parameters: customerId must reference an existing customer, and the approval.token is bound to these exact arguments — a semantic the nested schema cannot express. However, date, time, and service are left entirely to their patterns/schema, so coverage is partial.

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 specific verb and resource ('Create a booking') and narrows scope with two hard constraints: the customer must already exist and the slot must be a free 30-minute one. This is unmistakably distinct from cancel_booking, check_availability, and request_approval, so the agent can select it without opening any schema.

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 names the gating prerequisite and its source ('REQUIRES a prior approval from request_approval bound to these exact arguments'), which is exactly the alternative tool an agent must call first. It stops short of stating failure conditions or exclusions (e.g. what to do if the slot is not free, or that the approval is single-use).

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