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

Annotations already establish that this is a non-read-only, open-world, non-idempotent, non-destructive operation. The description adds important behavior not captured there: it sends a 6-digit SMS code to the user's mobile and must be followed by confirm_booking. It does not describe failure modes, rate limiting, or duplicate-request behavior, but the key side effect and workflow dependency are disclosed.

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?

The description is three short sentences, front-loads the main action and precondition, and then gives the operational sequence. Every sentence contributes to correct invocation or follow-up behavior.

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 mutating booking-initiation tool with no output schema, the description provides the essential flow: start the request, expect an SMS code, ask the user for it, and call confirm_booking. It also includes the user-facing prerequisite of reading back trip and fare, which is enough for an agent to invoke the tool correctly.

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 100%, so the parameter names, constraints, and per-field descriptions already do most of the work. The description adds useful context that quote_id must correspond to a quote the user has agreed to and that mobile receives the code, but it does not meaningfully expand semantics beyond 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?

The description states a specific action—starting a booking request for an already-agreed quote—and immediately names the follow-up tool confirm_booking. It clearly distinguishes the initiation step from confirmation and from quote retrieval.

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?

It specifies the precondition (the user has agreed to a quote), the workflow after calling (text code, ask user for it, call confirm_booking), and a sequencing constraint (only after reading trip and fare back to the user). This is explicit enough to guide both when and how to use the tool.

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