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

With no annotations provided, the description carries full behavioral burden. It discloses the cryptographic method (ed25519), the verification target (service's public key), and the return content (signature validity and txids). It does not explicitly state read-only behavior, but 'verify' strongly implies it.

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 filler. The action and primary resource are front-loaded, and the return values are stated efficiently. Every sentence earns its place.

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 single-parameter tool with no output schema, the description covers the essential behavior and return values. It lacks explicit error-handling or edge-case details, but the core information needed to invoke the tool correctly is present.

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?

The input schema only defines orderId as a string with no description. The description implies orderId identifies the order whose receipt to verify, which adds meaning beyond the schema. However, it does not explicitly state the parameter's purpose or expected format, leaving some inference required.

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 a specific verb ('Verify') and resource ('an order's ed25519-signed receipt against the service's published public key'). This is distinct from siblings like order_status or ledger, 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?

The description provides clear context: use this tool when you need to verify an order's receipt signature. It does not explicitly mention alternatives or exclusions, but the tool's purpose is distinct enough that no direct competitor exists among the siblings.

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