processInstance_setVariables

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

Without annotations, the description carries the full burden. It successfully discloses the destructive overwrite behavior ('Existing variables are overwritten') and state requirement ('active'), but omits transactional semantics (atomicity), side effects on process execution, or failure modes.

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?

Three sentences with zero waste: first establishes scope, second specifies input format, third warns of overwrite behavior. Information is front-loaded and every sentence earns its place.

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 empty input schema, lack of annotations, and absent output schema, the description provides minimal viable coverage of the operation. However, it omits return value details, specific parameter names, and error handling that would be necessary given the poor structured data richness.

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?

With zero schema-defined parameters (baseline 4), the description compensates by specifying the expected input structure: 'Provide a map of variable names to typed values.' This adds critical semantic context that the empty schema cannot provide.

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 specific action (add or update), resource (variables), target (active process instance), and distinguishes from sibling tools by emphasizing 'multiple variables' and 'single call' to differentiate from processInstance_setVariable.

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 efficiency benefits ('single call') but does not explicitly state when to use this versus the singular processInstance_setVariable or task_setVariables. It mentions 'active process instance' implying state requirements but lacks explicit prerequisites or error conditions.

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