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

Annotations already declare readOnlyHint=false, idempotentHint=false and openWorldHint=true, so the write/non-idempotent character is known. The description adds real context beyond that: immediate execution with no confirmation step, an outbound customer confirmation email, and a documented conflict failure mode ('Fails if the team member is already booked'). Auth/permission requirements are still unspecified.

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?

Four dense sentences, all load-bearing: purpose and side effect first, then prerequisites, then conditional parameters, then failure mode. No filler or repetition of the title.

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 the annotations cover the safety profile. The description covers prerequisites, conditional requirements and the conflict failure, leaving only minor gaps such as behavior if the confirmation email fails or any rate/permission constraints.

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 compensates by encoding conditional parameter requirements that the schema does not express: customerEmail for online bookings, customerEmail or customerPhone for in-person, and the source of teamMemberId/timezone. It could say more about meetingAddress and title, which remain purely schema-defined.

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 ('Creates a new appointment on the connected Nexwin account') plus the immediate side effect of emailing the customer a confirmation. This is distinguishable from read-oriented siblings like get_bookings and from reschedule_booking without opening either 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?

Gives concrete prerequisites ('Get teamMemberId and timezone from list_team_members first') and explicit branching rules for meetingType ('Online bookings require customerEmail ... in-person bookings need customerEmail or customerPhone'). It stops short of stating when NOT to use this tool, e.g. pointing at reschedule_booking for existing appointments.

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