create_layer

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

Annotations already declare the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=false), so the bar is lower. The description usefully discloses the upsert semantics and the optional current-layer side effect, which the annotations do not. However, it does not say what happens to existing attributes when the layer already exists, and there is tension between the 'update it if it exists' upsert framing and idempotentHint=false.

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?

One sentence, front-loaded with the primary verb and resource, with the upsert caveat and the optional side effect attached efficiently. No filler, though the brevity leaves the update semantics underspecified.

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 no explanation. But for a mutation tool in a toolset that also contains update_layer and set_current_layer, the description never resolves which tool owns which behavior or what an overwrite does to unspecified attributes, leaving the agent with a real ambiguity.

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 60% (color, linetype, lineweight are documented in-schema). The description adds meaning for the undocumented make_current parameter ('optionally make it current'), but the equally undocumented name parameter gets nothing beyond its self-evident title. This is around the baseline given partial schema coverage.

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 (Create) and resource (layer), plus the non-obvious upsert behavior ('or update it if it exists'). It stops short of differentiating from the sibling update_layer, which performs a similar mutation, so the agent must still guess which to pick.

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 prefer this over update_layer or set_current_layer, even though both siblings cover parts of this tool's behavior (updating a layer, making it current). The description asserts an upsert rule but never says when an agent should call this vs. those alternatives.

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