kaiten_add_card_subscriber

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the action and does not mention whether adding an existing subscriber is idempotent, whether special permissions are required, what side effects occur (e.g., notifications), or how errors are surfaced.

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 a single, clear sentence with no filler. It is front-loaded and an agent can parse it instantly.

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 mutation, the description gives enough to invoke the tool with card_id and user_id. However, with no annotations and no output schema, key contextual details such as idempotency, permission requirements, and expected behavior on duplicate subscriptions remain unstated.

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 coverage is 100%, and the schema already documents both parameters clearly ('Card ID' and 'User ID to subscribe'). The description adds minimal semantic value beyond the synonym 'watcher', so the baseline score of 3 is appropriate.

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 specific verb ('Add'), a specific resource ('subscriber (watcher)'), and the target ('a Kaiten card'). It clearly distinguishes this from related siblings like kaiten_remove_card_subscriber and kaiten_add_card_member.

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 intended use is implied by the verb and resource: use this when you need to add a watcher to a card. However, it does not explicitly compare itself to alternatives like kaiten_add_card_member, kaiten_remove_card_subscriber, or kaiten_list_card_subscribers, and gives no guidance on when not to use it.

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