Book an appointment

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

Annotations already declare readOnlyHint=false, openWorldHint=true, idempotentHint=false, and destructiveHint=false, so the write/non-idempotent profile is covered structurally. The description adds genuinely new behavior: the confirmation prerequisite and the alternate return of a booking link when no customer account is configured. It stops short of describing failure modes (e.g. a slot taken between lookup and booking).

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 short sentences, each carrying a distinct rule (purpose, confirmation gate, parameter provenance, no-account fallback), with the operational constraint front-loaded. No filler and nothing repeated from the schema.

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 three-required-parameter mutation tool with no output schema, the description covers the critical agent-facing concerns: prerequisite conversation state, where starts_at comes from, and one known return variant (booking link). It omits what a successful booking returns or how a taken slot is surfaced, which is a modest remaining gap.

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 100%, so the baseline is 3, but the description adds provenance semantics the schema does not: starts_at must be copied verbatim from find_available_slots and the fields must be confirmed with the person first. business and service_id sourcing is left to the schema, which already documents their origins.

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?

Starts with a specific verb+resource ('Book a service') and scopes it to the customer account configured on this server, which distinguishes it cleanly from siblings like find_available_slots and cancel_appointment. The opening sentence alone lets an agent identify the operation.

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 an explicit gating condition ('Only call this after the person has explicitly confirmed the business, service, day, time and price'), a dependency ordering rule (starts_at must be copied exactly from find_available_slots), and a fallback path when no customer account exists. This is when-to-use, when-not, and alternative behavior all in one.

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