appearance_list

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

With no annotations present, the description carries the full burden and does disclose the return envelope (items/total/truncated) and default scope behavior, which are the traits an agent most needs here. It stops short of stating read-only guarantees or any permission/precondition context.

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?

Scope statement is front-loaded in the first sentence, followed by the return shape and a single compact example. No filler, and each sentence contributes distinct information.

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?

There is no output schema, so describing the returned fields and the truncation flag is essential and is done here. All five parameters are covered by schema plus description, and the default-scope semantics are spelled out, leaving nothing an agent needs before calling.

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 100%, so the schema already documents each parameter; the description adds value by explaining the interaction between library and in_design (omitting library means all libraries) and by showing a concrete example call. It does not add format or edge-case detail beyond that.

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 (list) and resource (appearances / visual look) plus the three scoping modes: one library, all libraries (default), or the active design. This clearly separates it from siblings like appearance_assign and appearance_set_color, which mutate rather than enumerate.

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?

Explicitly states the default scope (every library) and the condition that switches to design-only results (in_design=true), plus points to material_list_libraries for resolving library names. It lacks an explicit 'not for assignment' note, but the read-only listing framing makes the boundary clear.

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