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

Annotations already set destructiveHint=true. The description adds value by detailing the two outcomes (inline booking vs. affiliate link), clarifying that no actual booking may occur if no partner API is connected. No contradiction with 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?

Three sentences, front-loaded with purpose, conditional behavior, and no wasted words. Highly concise.

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 7 parameters (2 required) and an output schema, the description covers the main behavioral branches (inline vs. affiliate). It doesn't detail return format (output schema handles that) and assumes domain knowledge (option_id from find_options). Adequate but not exhaustive.

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% (all 7 parameters described). The description adds minimal extra meaning beyond schema; the only addition is explaining affiliate fallback behavior, which is not parameter-specific. Hence baseline 3.

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 starts with 'Book an option (showtime, ticket class, etc.)' clearly stating the verb and resource. It distinguishes from sibling tools like find_options (which finds options) and request_unsupported_booking (handles unsupported cases).

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?

The description explains two scenarios: if partner API connected, completes inline; otherwise returns affiliate deep link. This guides when to expect a confirmation vs. a link, but doesn't explicitly state when not to use or alternatives beyond implicit sibling differentiation.

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