verify-my-purchase

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

With no annotations, the description carries the full burden. It discloses that the tool is instructional/read-only (it 'explains' and 'Returns the command'), and it clarifies the scope (does not process payment itself, just generates a command). It doesn't describe side effects, but given the non-mutating nature implied, this is adequate though it could state explicitly 'does not execute the command'.

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 two sentences, front-loaded with the when-to-use clause and efficiently conveys purpose and output. No wasted words; it earns every phrase.

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 3 simple params, no output schema, and no annotations, the description is fairly complete: it states the workflow position, the exact output (command + explanation), and the endpoint involved. It could be slightly more specific about the command's nature (e.g., HTTP) and response format, but the essentials are covered.

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%, so baseline is 3. The description adds no direct parameter-specific details beyond the schema, but it does contextualize the parameters (e.g., 'transaction hash' relates to tx_hash, 'merchant's /receipt endpoint' to merchant_url). The schema already provides clear descriptions, so the description adds marginal value.

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 tool's purpose: 'explains how to redeem' a payment by turning a transaction hash into content, and it specifies the output ('Returns the command to run against the merchant's /receipt endpoint'). This is a specific verb+resource combination that distinguishes it from the informational sibling tools.

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 provides a clear temporal context: 'After you've signed and sent a payment'. This tells the agent when to use it, but it does not explicitly mention alternatives or when not to use it. Given the sibling list, the context is sufficient for a conditional workflow step.

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