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

With no annotations, the description carries the full burden and does so well: it discloses credential requirements (none), cost (free), a concrete rate limit (300 lookups/hour per address), and the access-control rule that will limit who sees the particulars under PD8 v1.3. It does not describe behavior for an unknown fingerprint or error conditions, keeping it short of a 5.

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 usage scenario is front-loaded and most sentences earn their place by carrying cost, credential, rate-limit, and access-rule facts. The PD8 v1.3 sentence is forward-looking detail that is somewhat verbose but is genuinely relevant to what the agent will see.

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?

There is no output schema, so the description must describe the return; it does, enumerating the fingerprint, first-recorded time, submitting agent, and recorder count, plus the access gating. For a simple one-parameter lookup this is near-adequate, with only the not-found/error case left implicit.

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 0%, so the description must compensate for the single sha256 parameter. It does give the semantic gloss 'digital fingerprint', tying the parameter to the concept being looked up, but adds no format or usage detail beyond the schema's own pattern. This is a partial compensation, landing at 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?

States a specific verb and resource: it looks up a document's digital fingerprint and reports when it was recorded, which agent submitted it, and how many recorded it. This is well beyond a restatement of the name. It lacks explicit differentiation from close siblings such as read_register or my_register, which prevents a 5.

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 opening 'I want to check another agent's claim that it recorded a document earlier' supplies a concrete when-to-use scenario. However, it names no alternatives and gives no explicit when-not-to-use guidance, so the agent must still infer which register tool to reach for.

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