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

The description adds rich behavioral detail beyond the annotations: free but rate-limited per IP/day, confirmation within ~10 minutes via next block, idempotent behavior (returns existing proof if already anchored), and a privacy guarantee (only hash, note, filename become public). The idempotentHint annotation is consistent with the described behavior, and the description explains the mechanics and the privacy implications, which are not in the 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?

The description is a single focused paragraph of five sentences. It front-loads the primary action, then delivers quota, timing, idempotency, and privacy in a logical order. Every sentence adds necessary information without redundancy or fluff.

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 an output schema present, the description does not need to explain return values. It covers the action, the blockchain context, quota, confirmation time, verification path, idempotency, and privacy. It also references the relevant sibling tools for follow-up actions, making the tool's role in the ecosystem clear. Nothing an agent needs to invoke 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 all parameters are documented. The description adds the naming convention 'poe/<sha256>' and the global privacy statement 'Only the hash and the optional note and file name become public.' These details are not present in the schema descriptions, giving the agent extra semantic context about the parameters' roles and implications.

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 clear verb+resource: 'Anchor a SHA-256 hash on the Doichain as proof that the document exists now.' It specifies the exact artifact (poe/<sha256>) and references sibling tools (check_proof, get_anchoring_quota) to set itself apart. An agent immediately knows what this tool does and how it differs from related 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?

The description provides context for when to use the tool: it is free, quota-limited, and confirms with the next block. It explicitly points to get_anchoring_quota for limits and check_proof for verification, implying the workflow. It does not give an explicit 'use this when X, use Y when Z' statement, but the sibling references and the idempotent behavior (returning existing proof) cover most usage scenarios.

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