Update n8n Credential

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

Annotations already indicate readOnlyHint=false and destructiveHint=false. The description adds valuable context that 'data' is 'merged with existing', clarifying that the update is not a full replacement. This exceeds what annotations alone convey, though it does not cover auth or 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 concise and front-loaded with the main action. However, the 'Args' section largely duplicates the input schema's parameter descriptions, adding redundancy. Still, the layout is clear and appropriate length.

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 tool's simplicity (3 parameters, no output schema), the description covers the essential behavior and the merge semantics. It is sufficiently complete for an AI to understand what the tool does and when to use it, though it omits return value details.

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 100%, so baseline is 3. The description adds the key nuance that the 'data' parameter is 'merged with existing', which is not fully captured by the schema's 'Updated credential data/secrets'. This provides semantic value beyond the schema.

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: 'Update an existing credential's name or data.' This uses a specific verb ('Update') and resource ('credential'), and distinguishes it from sibling tools like n8n_create_credential and n8n_delete_credential.

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 usage context (updating an existing credential) but provides no explicit alternatives or exclusions. It does not reference sibling tools like create or delete, leaving the when/why partly inferred from the tool name and description.

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