Layer Mask

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

Annotations indicate destructiveHint=true, and the description adds context: 'apply' merges the mask (destructive), 'delete' removes it. It explains effects beyond what annotations provide, though it could further detail consequences (e.g., reversibility). No contradiction with annotations.

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 two sentences: first sentence states purpose, second sentence lists actions. No wasted words, front-loaded with key information. Efficient and clear.

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?

Given the simple parameter (one required enum) and the presence of annotations, the description fully covers the tool's behavior. No missing information for an agent to select and invoke the tool correctly.

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?

The single parameter 'action' has an enum with 4 values, and the description explains each one (e.g., 'create' adds a reveal-all mask). The schema only says 'Mask action to perform,' so the description adds significant meaning and covers all enum values.

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 clearly states the tool's purpose: 'Creates or manages layer masks.' It lists specific actions (create, create-from-selection, apply, delete) with brief explanations, distinguishing it from sibling tools that deal with other layer operations.

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 implies usage by listing actions, but it does not provide explicit guidance on when to use this tool versus alternatives or when not to use it. No exclusions or context for choosing among actions are given beyond the basic definitions.

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