add_expression_control

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

With no annotations provided, the description carries full burden but only states the action without behavioral details. It doesn't disclose if this is a destructive operation, what permissions are needed, how it affects the layer, error conditions, or what happens on success/failure. For a tool that modifies layers, this is a significant gap in transparency.

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 a single, clear sentence with no wasted words. It's front-loaded with the core action and target, making it easy to parse quickly. Every word contributes directly to understanding the tool's purpose.

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?

Given the complexity of adding effects to layers, no annotations, and no output schema, the description is incomplete. It doesn't explain what an 'expression control effect' is, how it integrates with the layer, what the tool returns, or error handling. For a tool with 5 parameters in a creative context, this leaves too much undefined.

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 description coverage is 100%, so the schema fully documents all parameters. The description adds no additional meaning beyond implying the tool adds a control effect, which is already clear from the name. This meets the baseline for high schema coverage but doesn't enhance understanding of parameters like 'value' or enum choices.

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 clearly states the action ('Add') and target ('expression control effect to a layer'), making the purpose understandable. It distinguishes from siblings like 'add_loop_expression' or 'add_wiggle_expression' by specifying it's for adding a control effect, not a specific expression type. However, it doesn't explicitly differentiate from 'apply_effect' or other effect-related tools, which keeps it from a perfect score.

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 no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing an existing composition/layer), compare to similar tools like 'apply_effect', or specify use cases (e.g., for dynamic animations). This lack of context leaves the agent to infer usage from parameters alone.

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