set_mask

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

The description adds meaningful behavioral detail beyond the annotations: it explains the masking behavior, notes that maskType is only applied when enabling, and states the return shape ({ ok, nodeId }). This goes beyond the minimal readOnlyHint/destructiveHint annotations without contradicting them.

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 concise sentences, front-loaded with the core purpose and followed by parameter usage and return information. Every clause earns its place, with no fluff or redundancy.

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?

For a simple mutation tool with no output schema, the description adequately covers what the tool does, how to use it, and what it returns. It lacks details about potential errors or prerequisites, but these are not critical for a well-scoped setter operation. Sibling context does not demand more.

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 parameters are already documented structurally. The description adds semantic value by explaining that maskType applies only when enabling, and by enumerating the enum values inline, reinforcing the schema's meaning.

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 a specific verb ('Set whether a node is a mask') and clearly defines the resource and behavior ('a mask clips its later siblings to its own shape'). It also distinguishes the tool from the many sibling set_* tools by explaining the unique mask semantics.

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 provides clear context for when to use this tool: when you need a node to act as a mask by clipping later siblings. It does not explicitly mention when not to use it or name alternative tools, but the usage scenario is evident and no direct alternative exists among siblings.

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