n8n_update_variable

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the mutation intent ('Update') but does not explain partial versus full update semantics, validation of type/value, behavior when the ID is not found, or any side effects.

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 short and free of fluff, but it is under-specified for a mutating tool with four parameters. Conciseness is fine, yet the sentence provides little detail beyond the tool name.

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 no annotations, no output schema, and a four-parameter mutation tool, the description is incomplete. It does not explain update behavior, error conditions, return values, or how the parameters interact, leaving an agent without enough context to call the tool confidently.

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 input schema already documents most parameters: id, key, and value have descriptions, and type is defined by an enum. The description adds no additional parameter meaning, but with 75% schema coverage the schema does the heavy lifting, so a baseline score is appropriate.

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 ('Update') and resource ('environment variable'), clearly identifying the operation and distinguishing it from sibling tools like n8n_create_variable, n8n_list_variables, and n8n_delete_variable. The resource name matches the tool name and the overall n8n variable context.

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?

No guidance is provided about when to use this tool instead of alternatives such as n8n_create_variable, n8n_list_variables, or n8n_delete_variable. There is also no mention of prerequisites like the variable needing to already exist or whether this should be used for partial updates.

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