create-variable

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

With no annotations provided, the description carries the full burden. It discloses licensing requirements and data format constraints (compact JSON), which are useful behavioral traits. However, it doesn't cover other important aspects like error handling, permissions needed beyond licensing, whether the operation is idempotent, or what happens on duplicate keys. The description adds some value but leaves gaps for a mutation tool.

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 appropriately sized with three sentences. The first states the purpose, the second adds licensing and use context, and the third provides critical formatting instructions. It's front-loaded with the core action. However, the licensing note could be integrated more smoothly.

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 a mutation tool with 3 parameters (0% schema coverage), no annotations, and no output schema, the description is incomplete. It misses parameter explanations, error conditions, response format, and detailed behavioral context. The licensing and formatting notes are helpful but don't compensate for the overall gaps in a creation operation.

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 description coverage is 0%, so the description must compensate. It doesn't explain what 'clientId', 'key', or 'value' represent, their formats, or constraints. The note about compact JSON applies to arguments generally but doesn't clarify individual parameters. For a tool with 3 required parameters and no schema descriptions, this is inadequate.

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 verb ('Create') and resource ('new variable in n8n'), making the purpose unambiguous. It distinguishes from siblings like 'delete-variable' and 'list-variables' by specifying creation. However, it doesn't explicitly differentiate from other creation tools like 'create-workflow' or 'create-project' in terms of when to choose one over another.

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 some context with the note about requiring an n8n Enterprise license, which implies when NOT to use it (without proper licensing). It mentions variables can be used across workflows, giving a hint about use cases. However, it lacks explicit alternatives (e.g., when to use this vs. other storage methods) or clear prerequisites beyond licensing.

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