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

Annotations only cover safety (readOnly/openWorld/non-destructive), and the description adds real behavioral context beyond them: only a salted hash leaves the server, anchoring takes hours, the exact proof format, and the $0.005 USDC x402 payment flow across four chains. This is the kind of detail an agent cannot infer from annotations.

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-loads the core action and price/verification details follow in a logical order; every clause carries information. It is on the long side, but the length is justified by pricing and chain information that the agent needs.

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 compensates fully: it explains what is returned (base64 .ots proof), the verification path, the privacy model, cost and payment rails. Nothing needed to call it 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%, so the schema already documents all three parameters, and the description largely restates them (text, hash as alternative to text, URL bytes). The free-sample example input adds minor invocation guidance, but nothing materially beyond the schema earns more than the 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?

Names a concrete verb (timestamp), the mechanism (OpenTimestamps on Bitcoin), the accepted inputs (text, SHA-256 hash, URL) and the returned artifact (base64 .ots proof). An agent can distinguish it from the verify sibling and from iota_notarize without opening the schema.

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?

Explicitly routes the agent to btc-timestamp-verify for the block/proof and lists concrete use cases (contracts, AI outputs, datasets, invoices, web evidence). It lacks an explicit when-not-to-use note (e.g. versus the IOTA notary siblings), but the context is clear.

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