sketch_constrain

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

With no annotations, the description carries the full burden and does so thoroughly: it discloses atomicity ('nothing is kept on failure'), specific failure modes and details fields, and the shape of the return value. This is unusually complete behavioral context 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 key action and atomicity guarantee are front-loaded, followed by a dense but necessary type reference, failure behavior, return shape, and a single illustrative example. Every sentence contributes useful information with no padding.

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 tool that can accept up to 500 heterogeneous constraints with no output schema, the description covers entity sourcing, valid type/parameter pairings, error behavior, atomicity, and return structure. An agent has enough information to invoke it 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?

Schema coverage is 67%, and the description compensates well by mapping each constraint type to its required parameter shape (e.g., coincident point/entity, tangent curve1/curve2, fix entity/fixed). It also gives a concrete example and notes the fix special case, adding real meaning beyond the complex discriminated union.

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 starts with a precise verb and resource: 'Add geometric constraints in order, all or nothing.' It also distinguishes the operation from neighboring sketch tools by focusing solely on constraints rather than drawing or dimensions.

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?

It explains where entity references come from ('sketch_draw refs, sketch_get') and the all-or-nothing execution model, which gives clear context. It does not explicitly contrast with alternatives such as sketch_dimension, so it stops short of a full when/when-not guide.

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