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

Annotations declare this is a non-readonly, non-idempotent, open-world operation, and the description adds the context that matters most: each call has a concrete cost ($0.02 USDC or credits) that varies by mode, that a wallet path needs no account while the account path spends credits, and that the tool will not accept the payload itself. It also bounds the claim being made ('proves the hash is unchanged, not that content is true'), which prevents misuse of the receipt.

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 compact and front-loaded: purpose first, then pricing, then the proof's limits and the client-side hashing instruction. The telegraphic pricing sentences ('Hash Stamp is the wallet price: $0.02 USDC, mode hash_only, no account') are dense but readable, though they partly duplicate the mode enum's description.

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 five parameters, one required, full schema coverage, and no output schema, the description covers the decisions an agent must make: which mode, what it costs, and the hard rule against sending content. The remaining gap is that nothing describes what a receipt looks like or how to retrieve/verify it later, which matters when no output schema exists.

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 description coverage is 100%, so the schema already documents all five parameters, including the mode enum and its per-mode pricing. The description largely restates the mode pricing rather than adding new meaning, and says nothing about sources, agent_label, or subject_label beyond what the schema provides. Baseline 3 is appropriate.

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 opens with a specific verb and resource: 'Mint a receipt for a SHA-512 content hash,' which tells an agent exactly what is produced and from what input. It also implicitly scopes the tool by clarifying that the stamp proves the hash is unchanged, not that the content is true, which separates it from provenance/truth-verification siblings. It stops short of naming a sibling or explicitly contrasting with verification 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?

Guidance is present but indirect: 'Hash client-side first. Do not send the payload' is a clear precondition, and the per-mode pricing implies which mode to choose for which need. However, there is no explicit when-to-use/when-not statement, no statement of what source_snapshot versus source_archive is for, and no mention of when to prefer a verification sibling instead.

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