Add Card Blocker

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

Annotations already communicate that this is not read-only, not idempotent, and not destructive, so the description does not need to restate those. It adds the behavioral note that the return value is the created blocker object and clarifies that both reason and blockerCardId can coexist. However, it does not disclose any side effects beyond creating a blocker, such as how this affects the card's state or whether repeated calls create duplicates.

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 short, front-loaded with the core action, and every sentence earns its place. The at-least-one constraint and the illustrative both-field example are concise and directly useful. There is no redundant filler or repetition of schema property details.

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 straightforward creation tool with one required parameter and no output schema, the description provides the essential invocation details: the required input relationship and the return value. It could be more complete by naming related operations or describing the created blocker object's structure, but these are not blocking gaps. The description is adequate for an agent to call 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 schema already documents all four parameters at 100% coverage, so the baseline is 3. The description goes beyond the schema by explicitly stating that at least one of reason or blockerCardId must be provided, which is a critical constraint not enforced by the schema itself. The concrete example of combining both fields also adds meaningful semantic value.

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 opens with a specific action and resource, 'Block a card,' and then gives useful detail about the required inputs and return value. It is clear and not tautological because it adds the at-least-one constraint and the returned blocker object. However, it does not explicitly differentiate itself from sibling tools like kaiten_update_card_blocker or kaiten_release_card_blocker.

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 does not say when to use this tool instead of alternatives, nor does it name any sibling tools or exclusion conditions. It gives parameter-level guidance about reason and blockerCardId, but that is about how to call the tool, not when to choose it. 'Block a card' states the purpose but provides no explicit usage context or exclusions.

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