add_arc

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

No annotations are provided, so the description carries the full burden. It does not disclose any side effects, such as whether the arc is added to the sketch permanently, whether the sketch must be active, or what happens on failure. This is a significant gap for a mutating 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 concise and well-structured: first a one-liner, then a compact list of kinds and their parameters. Every sentence provides necessary information with no fluff.

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 description covers the main semantic aspects of the parameters and kinds, but because there is no output schema or annotations, it omits behavioral details (e.g., return value, side effects). For a tool with 9 params and varied kinds, it's adequate but not fully complete.

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 description adds significant semantic meaning beyond the bare schema: it explains the three kinds and which parameters are used for each, and notes the meaning of sweep_radians (positive = CCW). The schema has 0% coverage, so this compensation is essential.

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 the verb 'Add' and the resource 'arc', with specific kinds and parameters for each. It distinguishes from siblings by specifying arc-specific parameters, though it doesn't explicitly differentiate from other add_* tools.

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 implies usage by listing kinds and required parameters, but doesn't explicitly say when to use this tool vs alternatives like add_circle or add_spline. It provides enough context for selection but lacks explicit 'when not to use' guidance.

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