watch_create

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

With no annotations, the description carries the burden of behavioral disclosure. It does add useful context: the webhook is signed)Skip, and there is a per-item daily cost via x402. However, it does not mention that this creates a persistent watch, what triggers the webhook beyond 'trip', or what the response contains.

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?

The description is one short, efficiently worded sentence that front-loads the core action and includes important billing and delivery details. 'Signed webhook on trip' is terse but understandable in context.

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?

Given the tool has nested conditional item schemas and no output schema, the description is incomplete about return values and what happens when requirements are met. It compensates somewhat by mentioning the webhook and pricing, but an agent still lacks context about the response or how payment is handled.

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 fully explains items, days, and webhookUrl. The description adds pricing context and the fact that multiple items are billed separately, but it does not clarify parameter semantics beyond what the schema already provides.

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 tool's domain (watching Base balances or USD prices) and the event condition (signed webhook on trip), which distinguishes it from sibling tools like watch_delete and watch_get. However, it never explicitly says 'create a watch' — that is only implied by the tool name.

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?

No guidance is given about when to use this tool instead of alternatives such as watch_delete or watch_get. There is no mention of prerequisites, payment setup, or scenarios that would favor one sibling over another.

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