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

Annotations (readOnlyHint=false, openWorldHint=true, destructiveHint=false) establish that this is a non-destructive write, and the description adds the genuinely useful behaviour: the request goes to a human team who 'will be in touch', and the call returns a ticket reference and reply time that must be relayed. It does not warn that repeated calls create separate tickets (relevant given idempotentHint=false) or that the handoff is asynchronous with no guaranteed SLA, which keeps it off a 5.

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?

Front-loaded with purpose, then alternatives, then the parameter decision tree, then the follow-up obligation — a sensible order with no filler. Some sentences are long and stack multiple clauses, but each one carries a distinct instruction.

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 an open-world, non-idempotent write with no output schema, the description covers purpose, exclusions, credential selection, message authoring, and even the return payload (ticket reference and reply time). An agent could call this correctly with no further inference.

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 would be 3, but the description adds real routing logic the schema only hints at: taskId when the booking was made in this chat, otherwise reference plus email/mobile, or just email when there is no reference. It also specifies message content ('in the traveller's words, with what they want and why'). The enum values for topic are left to the schema.

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 ('Send the traveller's request to Vuelo's support team') and explicitly scopes the tool as the catch-all for tasks 'the other tools cannot do, or wants a person'. That single clause differentiates it from every sibling in the list (cancel_booking, change_package_flight, get_support_ticket, etc.) without the agent needing to open a 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 explicit positive conditions (change dates/names after paying, refund question, payment problem, complaint, anything) and an explicit negative with the correct redirect: 'To cancel a booking made in this chat, use cancel_booking first'. It also resolves the ambiguous middle case by noting cancel_booking raises the request itself when Vuelo's team must act.

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