ae_setExpression

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

Annotations already declare a non-destructive, non-open-world mutation, so the safety profile is covered. The description adds a genuine post-condition — the expression error is returned if evaluation fails — which is useful for error handling. It does not state whether an existing expression is overwritten, whether the property must already be an expression-enabled property, or whether errors throw vs. return.

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?

A single dense sentence that front-loads the action, then the clearing semantics, then the path syntax, then the return behavior. No filler and nothing redundant with the schema.

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 4-parameter mutation with no output schema, the definition covers the hard parts: property addressing, expression clearing, comp selection via compositionName, and error reporting. Missing only minor details (overwrite behavior, what an expression error looks like), so it is nearly complete.

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 only 50% (only layer and compositionName are documented), but the description compensates well for the two bare parameters: it explains the accepted forms of `property` (aliases vs. a "Effects>...>..." / "Contents>..." path) and that `expression` is cleared by passing an empty string. This meaningfully exceeds the schema.

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?

Specific verb + resource: sets (or clears with an empty string) an expression on a property. It goes further than the name by enumerating what counts as a property (aliases like position/scale/rotation, or a hierarchical path like "Effects>Gaussian Blur>Blurriness"). It doesn't explicitly differentiate itself from close siblings such as ae_setEffectExpression or ae_applyExpressionTemplate, so it stops short of a 5.

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?

Usage is implied rather than contrasted: the description tells you how to clear an expression ("") and what property forms are accepted, but never says when to prefer this over ae_setEffectExpression (effect-property expressions) or ae_applyExpressionTemplate (canned expressions). An agent must infer the routing from the sibling names alone.

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