apply_shader

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

With no annotations, the description carries the full burden and does disclose the key behaviors: an import side effect ('Import (if needed)'), the destructive default (replace:true replaces all effects), and the append override. It does not cover failure behavior or permissions, but the destructive default and side effect are the critical disclosures for a mutation tool.

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?

Four sentences, front-loaded with purpose and followed by routing, alternative, and the append case. Mostly earns its place, though the 'properties may be keyed by...' sentence overlaps with the schema's own description of that parameter.

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 an 8-parameter, nested-object, no-output-schema mutation tool, the description covers the non-obvious essentials: import side effect, target routing, replace default, and append behavior. The remaining per-parameter details (visible, paintIndex) are already documented in the schema, so nothing critical is missing.

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 already 88%, so the baseline is 3; the description adds real meaning beyond the schema by explaining target routing (effect vs fill shaders) and the replace:false append semantics. The properties-keying sentence largely restates the schema description, so it is not fully additive.

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 ('Import (if needed) and apply a shader to a node') and immediately differentiates from the sibling by name ('Prefer this over set_effects when applying a SHADER'). An agent can tell it apart from set_effects and the fill/style tools without opening any schema.

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?

Gives explicit routing rules ('Effect shaders go on effects; fill shaders go on fills or strokes'), names the alternative and the condition that selects it ('Prefer this over set_effects when applying a SHADER'), and states the append case ('Pass replace:false to append'). Little is left to inference.

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