add_label_to_card

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 core action and purpose but does not mention side effects (e.g., idempotency, whether duplicates are allowed), required permissions, reversibility, or what the response contains. This is a significant gap for a mutation tool.

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 exactly two sentences, front-loaded with the action, and contains no superfluous information. Every word earns its place, making it highly concise and easy to parse.

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?

The tool is simple, but the description does not mention return values (no output schema), error conditions, or clarify the distinction from sibling tools like add_label and remove_label_from_card. Given the many similarly named sibling tools, the description should provide more contextual differentiation to ensure correct selection. The lack of behavioral details also contributes to incompleteness.

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%, with all four parameters (cardId, labelId, fields, detailLevel) already described in the schema. The description adds only the context of 'existing label', which slightly reinforces labelId semantics but does not provide additional parameter-level meaning. Baseline 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 clearly states 'Add a label to a card' with a specific verb and resource. The phrase 'with an existing label' differentiates it from sibling tools like create_label_on_card, which creates a new label. This is a specific, distinguishing purpose.

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 provides clear context for when to use: 'Use this tool to categorize a card with an existing label.' However, it does not explicitly mention alternatives or when not to use it, such as when creating a new label is needed. Thus, it lacks exclusionary guidance but gives clear usage context.

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