kaiten_add_card_child

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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, so the write-without-deletion profile is covered by structured data. The description adds the useful return fact (returns the child card) and clarifies no card is spawned. It is silent on the meaningful gap flagged by idempotentHint=false: what happens if the same child is linked twice, and whether the parent/child must be in the same board or space.

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 short sentences, action and scope first, with the clarifying negative statement immediately after. No filler, nothing buried.

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 low-complexity two-parameter link operation with annotations and an output schema present, the description covers the essential decision points and the return value. The remaining shortfall is the missing repeat-link / failure behavior, which matters given idempotentHint=false.

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 0%, so the two integer parameters carry no inline meaning beyond their names. The description compensates partially by establishing the parent/child relationship and the 'existing' constraint on child_card_id, but says nothing about the exclusiveMinimum:0 validity constraint or about cross-board/space compatibility.

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?

States a specific verb (link) and the two resources (child_card_id, parent_card_id), plus an explicit negative differentiator: 'does not create a card.' An agent can distinguish it from kaiten_create_card without opening the schema. It stops short of naming the sibling pair (kaiten_remove_card_child / kaiten_list_card_children) it sits beside, so not a 5.

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?

'Link an existing child_card_id' implies the precondition that both cards already exist, and 'does not create a card' implicitly steers creation requests toward kaiten_create_card. However, no alternative tool is named and there is no guidance on when linking is appropriate versus removing an existing link.

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