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

Annotations cover the safety profile (readOnly=false, idempotent=true, destructive=false), but the description adds crucial operational context: payment required ($222 USDC on Base/Arbitrum), x402 v2 PAYMENT-SIGNATURE header, POST to paid_url. That's a lot the agent can't get from structured fields alone.

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?

Front-loaded with purpose, then logistics, then pricing and URL. Reasonably efficient, but the payment and URL details are somewhat crammed; could be better structured without losing content.

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 paid, stateful tool with an output schema, the description covers the key non-obvious facts: payment protocol, auth header, endpoint URL, and pricing. Missing only explicit indication of what receipt object returns (output schema exists), so it's essentially complete.

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 parameters are fully documented in the schema (including the detailed idempotency_key semantics). The description adds no parameter-level detail, which is acceptable at high coverage – 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 states a specific verb (notarize/verify) and resource (evidence of work → signed receipt), naming the mechanism ('mint a portable signed receipt'). It doesn't distinguish itself from plausible siblings like cert or trust_report, but the purpose is clear.

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?

Says 'Use attest when you want the Embassy to notarize your work', which is an implied trigger, but gives no contrast with sibling verification tools (cert, prove_it, trust_report) or when-not-to-use. Adequate but thin.

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