construction_point

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

With no annotations, the description carries the burden and does so well: it discloses the two failure modes (INVALID_PARAMS with details{param, expected, got} for wrong entity kinds; FUSION_API_ERROR for unbuildable definitions), states that failed builds leave the timeline unchanged, and previews the return payload including a possible warning. It stops short of mentioning permissions or how the point appears in the timeline on success.

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?

Front-loaded with the verb, then a compact decision table, then pitfalls, return shape and two short examples — every block earns its place. The closing examples overlap somewhat with the table's method list, which is the only waste.

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 10-parameter mutation tool with no annotations and no output schema, the description covers the conditional parameter contract, accepted ref syntax and provenance, error behavior, and the return fields. An agent has everything needed to call it correctly without opening anything else.

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 already 100%, so the baseline is 3, but the description adds genuinely new meaning the schema cannot express: the conditional mapping of each `method` value to exactly which of the 10 optional fields must be supplied, plus the intersection/center semantics of each method. It also names accepted ref forms and the source tool for them.

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?

Opens with a specific verb+resource ('Create a construction point') and immediately scopes it with concrete use cases (joint origin, hinge center, sketch anchor). It also explicitly draws the boundary against the nearest confusable operation, sketch points made by coordinates via sketch_draw.

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 method table tells the agent exactly which case applies and which fields go with it, and it routes the coordinate-based case to sketch_draw and points the agent at inspect_query for refs. It doesn't address the neighboring construction_axis/construction_plane tools or assembly_create_joint_origin, but for this resource the guidance is clear.

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