update_feature

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

With no annotations, the description carries the behavioral burden; it explicitly signals mutation ('Modify', 'patched feature') and describes the return contract ('{ok, status, feature_id, ...}') as a way to check regeneration success. It does not mention persistence, permissions, or failure side effects, but the status-verification hint is meaningful behavioral context beyond the bare purpose.

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 dense but not bloated: purpose, usage example, parameter-keying rule, value-vs-expression rule, and return contract each occupy exactly one clause/sentence. No filler or repetition of required-parameter names.

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 5-required-parameter tool with nested update objects and no output schema, the description covers the key invocation details: how to address parameters, which field to use for which param type, and how to interpret the response. It does not spell out failure cases (invalid parameterId, malformed expression) beyond what the status contract implies, but that is a minor gap.

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 schema already describes parameterId, expression as 'Dimensional expression (quantity params)', and value as 'Literal value (enum/boolean params)'. The description adds concrete expression examples and clarifies keying by parameterId, but this largely reinforces rather than extends the schema semantics, so the baseline of 3 applies.

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: 'Modify parameters on an existing Part Studio feature', and reinforces with concrete iteration examples (extrude depth, fillet radius, oppositeDirection). It clearly delineates this as an update tool distinct from create_* siblings and delete_feature_by_name/delete_feature.

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 phrase 'for iteration' supplies clear context for when this tool is appropriate, and the examples show concrete modification workflows. It does not explicitly contrast this tool with recreating a feature or name the delete alternatives, so it stops short of a full when/when-not statement.

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