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

Annotations already declare readOnlyHint=false, destructiveHint=false, and idempotentHint=false. The description adds valuable behavior beyond that: a brief seat hold, a secure checkout link returned, no charge at this stage, and the connected-account prerequisite.

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 short sentences front-loaded with purpose and outcome. Every sentence adds distinct information: what happens, that nothing is charged, and the prerequisite.

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?

The description covers the mutation's behavioral outcome and prerequisite well, which is important since annotations only cover safety hints. However, with 0% schema coverage, the total absence of parameter guidance is a significant gap for correct invocation.

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% with 4 parameters, yet the description does not mention event_id, ticket_class_id, quantity, or promo_code at all. The agent must infer every parameter's meaning from bare names alone.

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 (start buying tickets), the resource (tickets for yourself), and the outcome (holds seats briefly and returns a checkout link). This is clearly distinguishable from sibling ticket tools like list_my_tickets, list_event_ticket_options, or rsvp_to_event.

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 clear context: 'for yourself' and 'Requires a connected account' define when this tool applies. It does not name alternatives (e.g., rsvp_to_event for free RSVP), but the usage context is unambiguous.

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