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

Annotations declare non-read-only, non-idempotent, non-destructive, open-world. The description adds real value beyond that: it discloses that it creates a Stripe payment link, that funds route to the pro's own Stripe account, and that the id must belong to the client's own bookings (ownership scoping). It omits failure modes and retry/idempotency risk, which matters for a non-idempotent money operation.

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?

Three tight sentences: action and id source first, return value second, eligibility gate last. No filler, no restating 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?

No output schema, so the description correctly explains the return (a Stripe payment link). For a non-idempotent payment-creating tool it could mention what happens on repeat calls or on failure, but the core information an agent needs to call it correctly is present.

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% (id has no description, tip says 'Dollars.'), so the description must compensate. It does: it clarifies that id comes from my_bookings and reinforces the dollars unit for tip. It does not state any id format or tip bounds, but the schema covers the minimum.

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?

Specific verb (tip) + resource (the pro / one of the client's appointments) + the source of the id (my_bookings). An agent can distinguish this from siblings like book_with_pro or set_booking_payments_and_policy 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?

States explicit trigger conditions: 'Only when the client asks to tip, and only for pros who take tips online.' This is a clear when-to-use plus a hard eligibility gate, which is exactly what an agent needs before invoking a payment-creating tool.

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