update_parameter

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

With no annotations, the description must disclose behavior and does mention it returns before/after values. However, it does not disclose side effects on dependent geometry, error behavior for invalid expressions, or undoability, which are important 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 description is two short sentences, front-loaded with the primary action and quickly noting the return value. Every sentence contributes meaning with no filler.

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 simple two-parameter update tool, the description is close to adequate but lacks details on prerequisites (parameter must exist), validation of expressions, and relation to sibling parameter tools. The mention of before/after values helps, but error behavior is absent.

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 schema provides no descriptions (0% coverage), and the description only loosely restates the two parameters: 'name' selects a user parameter and 'expression' is its new value. It does not clarify name format, required existence, or expression syntax, failing to compensate for the missing schema descriptions.

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 states a specific verb ('Update') and resource ('one user parameter's expression'), and clarifies it targets user parameters, distinguishing it from siblings like add_parameters and list_parameters. The mention of returning before/after values adds precision to the purpose.

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 the tool is used to modify an existing user parameter's expression, but it provides no explicit guidance on when to use this versus alternatives (e.g., add_parameters or edit_sketch_dimension) or any prerequisites. This leaves usage context implicit rather than actionable.

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