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

No annotations are provided, so the description carries the full burden and does so thoroughly. It discloses the privacy model (encrypted memo in a shielded zk-SNARK transaction), estimated duration of 10 to 60 seconds, consumption of one proof from the account, authentication requirements (account key in Authorization header), the return fields, the need to tell the user to keep txid and viewing_key, and error behavior (no proof is used on failure).

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 front-loaded with purpose and the sibling distinction, then moves through prerequisites, mechanics, duration, cost, returns, and error handling. It is dense and mostly earns its space, though it is longer than strictly necessary and could consolidate some details.

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?

Given that there is no output schema and no annotations, the description is complete enough for an agent to call the tool correctly: it covers the input format and how to obtain it, authentication, cost, timing, return values, and error behavior. Nothing material appears to be 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 description coverage is 100%, so the schema already documents the fingerprint parameter with a pattern and example. The description still adds meaningful semantic guidance beyond the schema by telling the agent to compute the hash locally over the exact bytes and giving an example command, which helps prevent calls with hashes computed over the wrong data.

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 first sentence states a specific verb and resource: it creates a private, dated proof that a file or data existed without sending the data. It also explicitly distinguishes itself from the sibling tool timestamp_text by naming it and describing the condition that selects 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?

The description gives explicit when-to-use guidance: use this when you already have the SHA-256 fingerprint, and use timestamp_text for short text. It also tells the agent how to obtain the hash locally, which is exactly the prerequisite an agent needs before calling the tool.

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