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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description does add two genuine behavioral facts beyond that: the call is free (no payment required) and the result deliberately excludes the paid envelope. However, it does not explain what the handoff contains or what happens next, leaving the agent with a partial picture.

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 short sentences, no padding, with the free/no-paid-envelope constraint stated up front. It is efficient, though the jargon ('x402 purchase handoff', 'chain-neutral') makes the sentences harder to parse than their length suggests.

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?

An output schema exists, so return values need not be explained, but the description still leaves the core agent question unanswered: what is a 'purchase handoff' and how does it relate to the sibling evidence-bundle tool? The negative guarantee is useful, yet the tool's role in the flow remains undefined.

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% with a single required receiptId described as 'PriorSeal receipt identifier', so the schema carries the parameter burden. The description adds nothing about the receipt identifier — no format, provenance, or what an invalid id does — so baseline 3 applies.

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?

States a verb ('Get') and a resource ('Evidence API envelope'), but the actual returned artifact is described as a 'free x402 purchase handoff', which obfuscates what the tool really returns. Crucially, it never distinguishes itself from the sibling priorseal_get_evidence_bundle, so an agent cannot tell which of the two to call.

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?

There is no statement of when to use this versus priorseal_get_evidence_bundle or priorseal_get_receipt, and no prerequisites or exclusions. The only implied guidance is the negative note that the paid envelope is not returned, which hints at a workflow step but never names it.

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