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

The description adds meaningful behavior beyond annotations: recovery requests never reveal whether a reservation matched, the email is sent only to the email on file with no recipient override, and email changes are handled externally. This gives the agent important privacy and side-effect context. No contradiction with the annotations.

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 front-loaded with the core purpose, then gives usage alternatives, privacy behavior, and a support pointer. Every sentence adds useful information without fluff; the structure makes the tool's behavior easy to scan.

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?

Despite moderate complexity, the description covers all essential aspects: when to use each parameter combination, privacy safeguards, recipient constraints, and escalation path. With an output schema present, no critical return-value detail is missing 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 coverage is 100%, and the description adds the crucial distinction between the two parameter sets: confirmation_number alone versus first_name, last_name, and email. It also clarifies that email is used only to find a match and that the confirmation goes to the address already on file, reinforcing and contextualizing 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: 'Resend a hotel reservation confirmation email.' It also distinguishes itself from sibling tools by explaining that the email contains the hotel confirmation number the guest can later use with lookup_booking or cancel_booking.

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 usage conditions: use the confirmation number from a successful lookup_booking call, or use the guest's full name and email when the confirmation number is unknown and the guest lacks card last four and check-in date. It also notes the recipient-restriction rule, which tells the agent when this tool is appropriate and what it cannot do.

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