set_active_channels

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

With no annotations, the description carries full disclosure burden. 'Replace' hints that the existing set is overwritten, but it does not say whether unlisted channels are disabled, whether an empty array clears the set, what validation failures look like, or whether the operation is undoable/requires a specific layer selection state.

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 sentence with no filler, and the target resource and key are front-loaded. It is efficient, though arguably too terse for a mutation with an unconstrained string array.

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?

The output schema covers return values, but for a mutation tool with zero annotation coverage and zero percent parameter documentation, the description should at minimum pin down the channel identifier vocabulary and replacement semantics. Those gaps leave the definition under-specified relative to its complexity.

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 0% and the description adds little: 'uid' is implied to be a layer UID, and 'channels' is only characterized as an 'active channel set' array of strings. The critical vocabulary — which channel identifiers are valid for Fill vs Paint layers — is undocumented anywhere, so an agent cannot reliably construct the call.

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 ('Replace') and resource ('a Fill or Paint layer's active channel set'), plus the lookup key (UID). It is clear what the tool does, but it does not distinguish itself from the sibling 'set_fill_channels', which plausibly overlaps.

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?

No guidance on when to choose this over 'set_fill_channels' or 'set_layer_properties', no prerequisites, and no note that 'replace' semantics vs incremental changes are a decision point. The only implied scope is 'Fill or Paint layer', which is stated as a capability rather than as a selection criterion.

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