set_mask

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

Beyond the annotations (readOnlyHint=false, destructiveHint=false), the description adds that the tool returns '{ ok, nodeId }' and explains the masking effect. It does not mention any side effects like impact on existing masks, but it provides sufficient behavioral 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?

The description is two sentences, front-loads the purpose, includes key parameter notes, and omits any unnecessary words. Every sentence is informative.

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?

With 3 parameters and no output schema, the description covers the core functionality, parameters, and return value. It does not discuss edge cases (e.g., what happens if node is already a mask), but it is sufficient for a straightforward mutation tool.

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%, but the description adds value by explaining that maskType is 'only applied when enabling' and lists the enums. This clarifies conditional usage beyond the schema's enum definition.

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 uses the specific verb 'Set' and clearly identifies the resource ('whether a node is a mask'). It explains the masking behavior ('clips its later siblings to its own shape'), which distinguishes it clearly from other sibling tools like set_visible or set_opacity.

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 for toggling mask status and optionally setting maskType when enabling, but it does not explicitly state when to use this tool versus alternatives (e.g., other set_* tools). No direct guidance on when not to use or prerequisites.

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