bind_variable_to_node

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

Annotations indicate readOnlyHint=false and destructiveHint=false. The description adds that unbinding is possible by passing null, that resolvedType must match, and the return format { ok, nodeId }. No contradictions, and it provides useful behavioral context beyond 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 a single paragraph of three sentences, front-loaded with the main action, followed by constraints and alternative tool. Every sentence adds essential information without waste.

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?

The description covers input parameters, constraints, return format, and sibling tool usage. With no output schema, it still provides the return shape. It could mention potential errors (e.g., invalid field), but overall it is sufficiently complete for a 3-parameter 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 significant meaning: it explains the 'field' parameter can take values like 'cornerRadius' to bind all corners, and 'variableId' can be null to unbind. It also specifies type matching requirements, which the schema lacks.

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 action: 'Bind a variable to a node field... or unbind by passing variableId: null.' It provides specific field examples (width, height, characters, etc.) and distinguishes from the sibling tool for paint bindings.

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 explicitly tells when to use the sibling tool ('To bind a fill or stroke color use bind_variable_to_paint instead') and advises using get_variable_defs for bindable variable IDs. It lacks explicit prerequisites or when NOT to use the tool, but the guidance is clear enough.

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