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

Annotations already mark it read-only and closed-world, and the description goes well beyond them: 0.10 USDC per call via x402 exact on Base, 10 signed-wallet free calls per rolling 30 days, X-Wever-Wallet-Proof must bind to the exact JSON arguments and route, POST endpoint, and an Ed25519-signed receipt in the return. It also scopes side effects explicitly (no page fetch, no account access, no merchant contact, no money movement).

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-loaded with the action and output, then constraints, then payment/auth mechanics, then pointers. Dense but nearly every clause carries operational weight; the payment/contract/homepage boilerplate is the only part that could be trimmed for an agent audience.

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 still tells the agent what the report contains (differing figures, dates, names and must/must-not/may wording, each quoted with its counterpart) and that it is signed. For a paid, wallet-authenticated tool, the cost, free-quota, and proof-binding requirements are all stated, so 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 description coverage is 100%, so the schema already explains source/translation, the optional labels, BCP 47 tags, format enum and size limits. The description only echoes that language tags are optional and that each difference is quoted with its paired passage; it adds no syntax or edge-case meaning beyond the schema, so baseline 3 applies.

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?

Specific verb and resource: submit the same passage in two languages and get back a report of differing figures, dates, names and obligation words. It even names the mechanism (word matching) and the artifacts returned (Ed25519 signed receipt), which distinguishes it from the many other '*evidence-check' and diff siblings.

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 sentence sets the usage condition clearly (two versions of the same passage in different languages), and 'it does not interpret meaning beyond that matching' tells the agent what class of question not to bring here. It stops short of naming an alternative sibling for related tasks such as contract-diff-check, so there is no explicit when-not routing.

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