x402 Trust watch: renew 30 days

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

With no annotations, the description carries the full burden. It usefully discloses the effect (adds exactly 30 days), the precondition (active watch), and that the same secret/credential is reused. It omits what happens on failure, whether renewal is idempotent, and any cost implications, so it is only partially transparent for a mutation 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?

Two short sentences with zero padding, and the core action is front-loaded ahead of the qualifier. Every word 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?

The tool is simple (one parameter, no nested objects) but has no output schema and no annotations, so the description is the only source of behavioral and return information. It covers the action and precondition but says nothing about the result or failure modes, leaving a modest gap.

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?

There is a single parameter (watch_id) with 100% schema coverage, and the schema already explains it as the id returned by x402_watch_create. The description adds nothing about the parameter, 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?

The description gives a specific verb and effect ("Add another 30 days") on a specific resource ("an active watch"), so the operation is unambiguous. It does not explicitly differentiate itself from sibling watch tools like x402_watch_edit or x402_watch_cancel, 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?

"an active watch" implies a precondition (the watch must exist and be active), which gives some usage context. However, it names no alternatives and gives no when-not guidance relative to x402_watch_edit or x402_watch_create, leaving the agent to infer the correct tool.

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