create_checkout_handoff

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

Describes behavior: creates a checkout/upgrade link and returns handoffUrl. Notes that agent cannot complete payment and must give URL to user. Annotations (readOnlyHint false, destructiveHint false) are consistent with this description.

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?

Concise, front-loaded description. First sentence states purpose, second explains behavior, third gives agent instruction, fourth and fifth provide usage conditions. Every sentence adds value without fluff.

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 2 required params, no output schema, and no nested objects, the description covers purpose, behavior, constraints, and usage guidelines completely. The output format is implied ({ handoffUrl }). No missing information.

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%. Description adds context to parameters: planId enums are explained with descriptions like 'one-time unlock' and reference to get_pricing; scanId context is repeated but clear. Additional value beyond schema justifies above 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 clearly states that it creates a human handoff URL for purchasing a report or subscription after a scan. It includes a specific verb (create), resource (handoff URL), and context (after scan complete). It also distinguishes from sibling tool unlock_report by noting when to prefer that tool.

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?

Explicitly states when to use: only when the report is paywalled (get_scan shows access.level teaser with payment_required true) and no free campaign is active. Provides clear alternative: during a campaign, prefer unlock_report.

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