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

Annotations only say it is a non-read-only, idempotent, non-destructive, closed-world write; the description goes well beyond that by disclosing the return payload (exact rule, plain-English read-back, hash, publishable flag, suggestions), the publishing path and its api_key requirement, cost ('Free'), and the exact error shape {error, field, got, reason, fix}. The 'same rule and the same hash' claim is consistent with idempotentHint=true and nothing contradicts 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 trigger is reasonably front-loaded, but the description is one dense run-on that re-states schema URLs and resource URIs already present in the input schema and tacks on error-format and 'explain and next' details. Most content earns its place, but the packaging makes it harder to scan than it needs to be.

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 six optional parameters, nested JSON, and no output schema, the description carries the burden well: it explains both input encodings, what is returned, the conditional publish flow and its credential requirement, and the error contract. An agent can call this correctly without opening the schema.

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 already 83%, but the description adds real meaning: words= and rule= are two encodings of the same bar producing the same hash, unreadable words are refused rather than guessed, and api_key is needed only for publishing. It does not clarify name or visibility beyond the schema, keeping it below 5.

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 states a concrete verb and artifact: turn a requirement ('bar') expressed in words or JSON into a canonical rule with a hash. It explicitly routes to the sibling check for the next step. It does not differentiate itself from the other siblings (more, prove), so it falls short of 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?

Gives a clear trigger ('Call when you know what you need from a counterparty and want it as an exact rule before you check anyone') plus sequencing ('Then call check(subject, rule=<the rule>)') and a ready-made alternative (library resources). No explicit when-not-to-use or contrast with prove/more, so not a 5.

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