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

The first lines disclose real behavior beyond the annotations: the open window is discarded and no further windows close, and a signed Ed25519 receipt is returned. However the appended standing-jobs sentence claims these tools "never move money, place orders or change state", which is directly at odds with a cancel operation declared destructiveHint=true and readOnlyHint=false. That boilerplate is actively misleading for this tool.

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?

Purpose and effects are front-loaded in the first two sentences, which is good. The remaining text is a large block of payment, authentication and contract boilerplate (x402 pricing, X-Wever-Wallet-Proof, contract and human URLs) that is repeated verbatim across the family rather than tailored to a one-parameter cancel call.

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 mutation the description covers effect, ownership, the read alternative, payment cost and the signed-receipt return, which is more than enough to invoke it correctly. The only real gap is the internal contradiction about not changing state, which undercuts otherwise complete coverage.

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 the single digest_id parameter is already documented with its pattern and origin at creation. The description adds only the ownership constraint that the digest must belong to the calling wallet, which is genuinely useful but modest; baseline 3 applies when the schema carries the burden.

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?

"Stop a digest owned by the calling wallet" gives a specific verb and resource, plus an ownership scope. It is trivially distinguishable from wever_digest-create and the read-only wever_digest-status, so an agent can route without opening any schema.

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 states the situation that calls for this tool (stop future windows, discard the open one) and explicitly routes the agent to wever_digest-status when it only wants to read a posted digest. No explicit when-not-to-cancel exclusion exists, and it does not distinguish itself from near-neighbours such as wever_schedule-cancel, so it stops short of a 5.

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