Create User Coordinate System

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

The description discloses a meaningful side effect beyond the annotations: a hidden reference sketch is created to anchor the UCS and should not be deleted. This is valuable behavioral context that the annotations do not convey. It does not contradict the provided annotations.

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 two sentences, front-loads the core action, and includes all essential caveats (API preview and hidden reference sketch). Every sentence earns its place with no redundancy.

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?

Given the high schema coverage, the description provides enough context for an agent to invoke the tool correctly. It covers the action, coordinate inputs, optional rotation, API status, and an important side effect. It could be slightly more complete by stating what the tool returns, but the rest is sufficient.

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 input schema already documents all 7 parameters with full descriptions, default values, and units. The description adds minimal extra meaning by summarizing the (x, y, z) origin and optional rotation, so the baseline of 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 uses a specific verb and resource: 'Create a UCS at (x, y, z) with optional rotation.' It clearly identifies what the tool does and is unambiguous among the sibling tools, especially since no other sibling creates a coordinate system.

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 when to use the tool by explicitly naming UCS creation, and the 'Fusion 2026+ UCS API, preview' qualifier gives some context. However, it does not provide explicit when-to-use vs. alternative guidance or state exclusions, so the guidance is only implied.

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