ae_addExpressionControl

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

Annotations already declare readOnlyHint=false, openWorldHint=false and destructiveHint=false, so the safety profile is known; the description adds essentially no behavior beyond purpose. It doesn't say the control is added as a new effect/entry on the layer, that it mutates the project state and is undoable, or what happens if a control with the same name already exists.

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 front-loaded sentence naming the app, the verb, the resource, and the valid control types. No filler, no repetition of 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 six-parameter mutation tool with no output schema, the definition covers purpose and control types adequately and annotations cover safety. The remaining gap is guidance about the unnamed/defaulted parameters and the value-type mapping, which the schema leaves half-undocumented.

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 50%: items, layer and compositionName are documented in the schema, while name and value are not. The description enumerates controlType values (matching the enum) but never explains the polymorphic `value` argument — e.g. that color expects an array of numbers and point expects a 2-element array — which is the biggest ambiguity an agent would hit.

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?

States a specific verb ('add') and resource ('an expression control') and enumerates the eight control types, so it is clearly distinguishable from ae_setExpression, ae_applyExpressionTemplate and ae_addEffect. It stops short of naming a sibling to contrast against, which keeps it from 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?

'To rig expressions against' implies the scenario (before wiring an expression to a control), but there is no explicit when-to-use, when-not-to-use, or prerequisite such as 'the layer must exist in the active comp' or 'use ae_setExpression afterwards to attach the expression'. Usage is inferable rather than prescribed.

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