blender_add_modifier

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

Annotations already mark the operation not read-only and not destructive; the description builds on this by clarifying that the modifier remains live and tweakable unless the apply sibling is used. This adds practical behavioral context beyond the structured hints.

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?

Two short sentences front-load the core action and add the key non-destructive distinction without wasted words. Every clause earns its place.

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 moderate-complexity mutation with no output schema, the description plus schema gives an agent enough to select and call the tool: required object/type, optional flags/properties, and guidance on whether to apply. It does not describe return values, but the absence of an output schema is partially offset by clear purpose and sibling routing.

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 67%: type, flags, properties, and response_format are documented in the schema, while name and object lack descriptions. The tool description itself adds no parameter-level meaning, but the two required parameters are largely self-explanatory and the schema covers the rest.

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 opens with a specific verb+resource ('Add a modifier to an object') and immediately distinguishes itself by labeling the operation non-destructive and naming blender_apply_modifier as the permanent counterpart. An agent can separate it from the apply-modifier sibling without opening the schema.

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?

It gives clear usage context: adding is non-destructive, and the caller can either use blender_apply_modifier to flatten the result or leave it in place for a live, tweakable result. It names the alternative but does not explicitly enumerate when not to use this tool; the guidance is clear rather than fully prescriptive.

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