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

Annotations already disclose that this is a non-read-only, non-idempotent, non-destructive, closed-world mutation. The description adds useful behavioral context by explaining that Studio defaults and Studio-owned fields are applied and that expectedSpecVersion guards against stale writes, but it does not describe the failure behavior when the version is stale or what the operation returns.

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?

The description is only two sentences and is front-loaded with the core action. Every sentence adds information: the first defines the operation, and the second states a required concurrency parameter and its purpose.

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?

Annotations cover the safety profile and the nested input schema richly documents layer structure, so the description need not explain return values or every paint property. Still, for a complex Studio-specific mutation that overlaps with project_add_layer, it does not clarify sibling selection or what 'Studio-owned fields' means, leaving a meaningful contextual gap.

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?

Top-level schema description coverage is reported at 0%, and projectId has no description in either the schema or the tool description. The description compensates partially by explaining that expectedSpecVersion prevents stale writes, while title and position are documented in the schema; the huge nested layer schema carries most of the remaining input semantics.

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?

The description gives a specific verb and resource: adding a map layer, scoped to Studio defaults and Studio-owned fields. It is clearly a write/add operation, but it does not explicitly distinguish this from the sibling project_add_layer tool, so an agent may still need to infer when Studio-specific addition is required.

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 description supplies one important usage prerequisite: expectedSpecVersion is required to prevent stale writes. However, it does not state when to use this tool versus project_add_layer or any other layer-creation path, leaving the main selection decision implicit.

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