x402 Trust watch: edit delivery URLs, sensitivity or events

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

With no annotations, the description carries full behavioral burden, and it does disclose one genuinely valuable trait: new URLs are validated first and a failed test leaves the old config untouched (atomic update). However, it omits other behavioral facts an agent needs for a mutation tool — the one-time bearer-secret auth requirement, reversibility of changes, and whether webhook/slack_url edits can be applied partially.

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?

Two sentences, zero filler, with the action and its scope front-loaded and the transactional guarantee immediately following. Every clause earns its place.

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 6-parameter mutation tool with no annotations and no output schema, the parameters are well covered by the schema and the description adds the key atomicity fact. What is missing is context on authentication (the required secret), the response/confirmation behavior, and precedence when multiple field groups are updated at once, leaving the definition minimally viable rather than complete.

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 documents all six parameters, including the 'omit to keep current' semantics and the max-5 URL constraint. The description only restates the three edit categories at a high level and adds no syntax, format, or edge-case detail beyond the schema, so the baseline of 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?

States a specific verb (Change) and resource (a watch) plus the three mutable fields (webhook URLs, sensitivity, subscribed events), so an agent knows exactly what the tool mutates. It does not explicitly name the sibling alternatives (create/cancel/renew), so sibling discrimination is left implicit rather than stated.

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 gives no when-to-use vs when-not guidance and never points to related siblings like x402_watch_renew or x402_watch_cancel. Usage is inferable from the verb, but nothing tells the agent under what conditions editing is the right call versus recreating or renewing the watch.

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