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

Annotations are all false, so the description carries the burden. It discloses that the grant is short-lived (60 minutes) and scoped to the customer's own bookings, which are important behavioral traits. It does not mention code consumption, rate limits, or error conditions, but the given details are substantive. This is a solid disclosure, earning a 4.

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?

Two sentences with no fluff. The first sentence states the core exchange and the grant's properties; the second gives actionable follow-up steps. Every word earns its place, and the key information is front-loaded.

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 tool with no output schema, the description tells the agent what the tool returns (a customer_grant) and how to use it. However, it omits the session_id parameter and provides no error or edge-case guidance. Given the moderate complexity, it is adequate but has clear gaps, warranting a 3.

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%, so the description must explain the parameters. It implicitly covers 'code' (the SMS code) and 'verification_id' (the ID from start_phone_verification), but it never mentions 'session_id' at all. With three parameters and two required, omitting one is a significant gap. The description adds meaning for the main flow but does not fully compensate for the schema's lack of documentation.

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 clearly states the verb 'Exchanges' with a specific resource (SMS code) and the outcome (customer_grant). It distinguishes itself from start_phone_verification by describing the follow-up step, and it scopes the grant to the customer's own bookings, making the tool's purpose unambiguous.

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 explicitly states that the tool exchanges the code from start_phone_verification and directs the agent to pass the resulting customer_grant to four sibling tools. This gives clear when-to-use context. However, it does not explicitly state when not to use it or mention any alternative flows, so it stops short of a perfect 5.

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