Watch Card

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

Annotations provide readOnlyHint=false and destructiveHint=false, and the description adds meaningful behavioral detail: subscribing causes notifications on update, comment, or status change. It transparently describes the side effect and trigger conditions, though it does not mention persistence, unsubscribing, or response details.

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 two concise sentences that front-load the action and then specify the concrete notification triggers. Every sentence earns its place with no filler.

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 simple two-parameter subscription tool, the description, schema, and annotations are largely sufficient: purpose, required parameters, and effect are clear. The main gaps are the immediate return value and guidance for unwatching, but these are not necessary to invoke the tool correctly.

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 input schema already documents both parameters with 100% coverage, including the card_number versus card_id distinction and where to find account_slug. The description adds no parameter-specific semantics, so the baseline score 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 states a clear verb and resource: 'Subscribe to notifications for a card.' It also clarifies the meaningful notification triggers, which helps distinguish this tool from siblings like fizzy_unwatch_card or fizzy_get_notifications.

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 explains what the tool does but does not explicitly say when to use it versus alternatives such as fizzy_unwatch_card or fizzy_get_notifications. There is also no mention of prerequisites, exclusions, or how to stop the subscription.

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