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

Beyond the annotations, it discloses the two traits an agent most needs: the call is metered ('Paid per call via x402 when payments are on') and the output is a signed, chain-anchored artifact rather than a mere lookup. This is consistent with readOnlyHint=false and destructiveHint=false, since the tool signs/anchors but destroys nothing. It doesn't say what happens when the envelope fails the structural check described in the schema.

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?

One dense sentence carries the core purpose and audience, with the payment caveat trailing in a second short clause. No filler, and the key noun ('receipt') is front-loaded, though the opening clause is long enough to be slightly harder to scan than it needs to be.

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?

With no output schema, the description correctly characterizes the artifact as signed and chain-anchored and time-bounded, which is the essential return-value context. The remaining gap is that receipt fields, format, and the actual cost are left to quantum_pricing rather than spelled out here, but nothing needed to invoke the tool correctly is missing.

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 all three parameters described, including the important 'envelope_sha256' alternative that keeps data local. The description adds no parameter-level meaning — the privacy-preserving digest option and the 'nothing is decrypted' check are both documented in the schema, so the baseline of 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?

The description gives a specific verb and resource — 'Get a signed, chain-anchored protection receipt' — and scopes it to 'envelopes sealed with the local Privi Vault tool,' which implicitly separates it from the vault_seal/vault_open siblings and from quantum_advantage_receipt. It never explicitly names a sibling to contrast against, so an agent must infer the boundary rather than read it.

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 states the conditions under which this applies (envelopes produced by the local Privi Vault tool, needing proof of encryption by a given time) and flags the payment precondition with a pointer to quantum_pricing. There are no explicit 'do not use this when…' exclusions, so it falls short of a full routing statement.

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