merge_down

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

No annotations are supplied, so the description carries the full burden. It reveals only that the operation returns the merged layer; it does not disclose that merging is destructive, whether it is undoable, what happens to blend modes/opacity of the lower layer, or any permission or format constraints. For a mutation with zero annotation coverage this is a serious gap.

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?

Two short, front-loaded sentences with no filler. The operation and its return value are stated immediately, and nothing is repeated from structured fields.

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 destructive layer operation with no annotations, no output schema, and an undocumented parameter, the description is too thin. It should at minimum state the destructive/undo implications and the accepted layer identifier format so an agent can invoke it safely.

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%, so the description must compensate. It does clarify that the layer parameter is optional and defaults to the active layer, which is genuinely useful, but it never says what identifier format is expected (name, ID, index) nor how the default is resolved when no active layer exists.

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 and resource ('Merge a layer ... into the layer below it') and adds the directional detail that separates it from flatten_image or delete_layer. It does not explicitly name a sibling for contrast, 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?

The only usage signal is the default of merging the active layer. There is no guidance on when to choose merge_down over flatten_image, arrange_layer, or delete_layer, and no stated preconditions such as whether the target must be a raster layer or whether the bottom layer can be merged.

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