surface_trim_cells

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

With no annotations, the description carries the full burden and does: it discloses that the design is not modified (trim input cancelled), that cells are temporary with no refs, what each cell contains, and the INVALID_PARAMS error for a wrong tool type. That is unusually complete behavioral disclosure for a preview operation.

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 key fact (it is a preview, nothing changes), then field details, then error and return shape. Slight redundancy: the cell fields are described in prose and then repeated in the Returns block, which costs a few tokens without adding information.

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?

Single required parameter, no output schema, yet the description fully documents the return object shape, cell fields, units, lifetime of the returned cells, and the error case. Nothing an agent needs in order to call it correctly is missing.

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 100% and the trim_tool property already documents accepted tool kinds, so the schema covers the parameter. The description still adds value by giving a concrete example call surface_trim_cells(trim_tool="origin:XY"), showing the expected value format beyond the enum-less string schema.

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?

States a specific verb and resource — a preview of a surface trim that returns the cells the cutting tool divides surfaces into. The phrase 'Preview of a trim' and the explicit note that nothing changes clearly distinguish it from the sibling surface_trim, which performs the actual cut.

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?

Gives concrete workflow guidance: pick the cells to remove by a point near them and pass those points to surface_trim. That tells the agent what the natural follow-up call is, though it never explicitly states the reverse condition (when to go straight to surface_trim without previewing).

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