Renew a watch (paid via x402)

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

With no annotations, the description carries the full burden. It discloses the period extension, pricing, budget reset, and reactivation behavior—substantial detail beyond a simple 'renews a watch.' It does not cover payment flow or failure states, but the disclosed traits are meaningful.

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 tightly written sentences with no filler. The first sentence covers the core action and effects; the second adds an important edge case. Each 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?

The tool is a mutation with no output schema and no annotations. The description covers the main effects but omits return values, payment details (despite the x402 mention in the title), and error scenarios. Given the complexity, this is adequate but has clear gaps.

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?

The schema has 0% coverage from the description, so the description must compensate. It implies watchId as the target and explains tier affects duration and price, adding meaning to the enum values. However, it never explicitly links these to the parameter names or mentions 'tier' and 'watchId' directly, so it only partially compensates.

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 clearly states the verb 'Extends' with a specific resource (a watch) and the specifics of duration (7 days, or 30 on *30 tiers), price, budget reset, and reactivation. This sharply distinguishes it from siblings like create_watch, pause_watch, and delete_watch.

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?

It provides clear context for when to use (renewing a watch for an additional period) and includes an edge case (reactivating paused watches). However, it does not explicitly mention alternatives or when not to use it, 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.