layer_update

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

No annotations are provided, so the description carries the full burden. 'Update' implies mutation but the description says nothing about permission/session requirements, whether unspecified fields are left untouched, reversibility, or side effects on related layers. Listing the mutable fields is the only behavioral signal.

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 compact sentence with no filler, and the field list is front-loaded after the verb. It is neither padded nor vague, though the dense comma-list is slightly harder to scan than a structured enumeration.

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?

An output schema exists, so return values need not be described. But for a 9-parameter mutation tool with zero annotation coverage and no schema descriptions, the definition omits the identity parameters, does not state that only supplied fields change, and gives no hint about failure modes or session handling.

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 0%, so the description must compensate, and it partially does: it maps name, visible, opacity, blend_mode, lock_alpha and clarifies that x/y are 'absolute offsets' rather than relative deltas, which the bare schema titles do not convey. However, session_id and layer_id are never explained, and optionality/partial-update semantics (all non-required params default to null) are left unstated.

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 ('Update') plus resource ('layer') and an enumerated list of mutable fields, so the agent knows exactly what the tool does. It does not differentiate itself from adjacent mutators such as layer_resize, transform_layer, or layer_reorder, which is the only thing keeping 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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives among the many sibling layer-mutation tools. The agent must infer that this is the general-purpose property editor rather than, say, layer_resize or transform_layer.

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