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

Annotations already declare readOnlyHint and idempotentHint, and the description adds valuable behavioral detail: it lists the possible statuses, the included block height/time/transaction/links, and interprets what a confirmed or expired proof means. This goes beyond the structured data without contradicting it.

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?

Three sentences with no waste: first sentence states purpose and the name format, second enumerates return values, third explains the meaning of confirmed/expired. The most important information is front-loaded.

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?

For a single-parameter, read-only tool with an output schema, the description covers the operation, the result semantics, and the interpretation of statuses. No essential calling context 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?

The input schema provides complete parameter documentation (format, length, acceptable prefixes) at 100% coverage. The description adds only the context that the hash is used as a name 'poe/<sha256>', which is a minor extra. This meets the baseline for high schema coverage.

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 uses a specific verb ('check') and resource ('SHA-256 hash anchored on the Doichain (name poe/<sha256>)'), clearly distinguishing it from siblings like anchor_proof (which creates the proof) and lookup_name (which looks up names generically).

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 clearly states the tool's function and the meaning of its results, giving clear context for when to use it. It does not explicitly name alternatives or exclusions, but the specific name pattern 'poe/<sha256>' and the focus on proof-of-existence status make the intended use unambiguous.

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