blender_drivers

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

Annotations already indicate this is a mutation tool (readOnlyHint=false, destructiveHint=false). The description adds the purpose and a feature ('real typed variables') but does not disclose side effects, prerequisites (e.g., active object), or whether existing drivers are overwritten. No contradiction with annotations, but the added behavioral context is minimal.

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 concise sentences with no filler. It leads with the main action and then provides illustrative examples, maximizing informativeness per word.

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?

While the description is clear on purpose and use cases, it lacks detail on several important aspects: the meaning of 'object' and 'data_path', the return format of 'list', and how to structure variables. With 8 parameters and no output schema, the description is not fully complete, though it provides a reasonable starting point.

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 75%, so most parameters are documented in the schema. The description adds meaning to 'variables' and 'expression' ('real typed variables and expressions') but does not clarify 'object' or 'data_path', which are undocumented in the schema. Since it does not fully compensate for the two missing descriptions, a baseline 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 states a clear verb–resource pair ('Add, list or remove drivers') and emphasizes 'real typed variables and expressions', which distinguishes it from sibling keyframe/animation tools. It also gives concrete examples (spin a wheel, bob with a sine), making the purpose immediately understandable.

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 provides usage context by stating it's 'useful for procedural motion that should not be baked', implying when to prefer it over keyframes. However, it does not explicitly name alternatives or give 'when not to use' conditions, so it falls short of a 5.

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