Update existing n8n credentials by modifying name, data, or node access restrictions. Supports partial updates for efficient changes.
Update an existing credential (name, data, or node access)
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | Credential ID to update | |
| data | No | Updated credential data (partial update supported) | |
| name | No | New name for the credential | |
| nodesAccess | No | Updated node access restrictions |
Changes observed during successful MCP inspections.
v2.2.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It only conveys that this is a mutation operation. It does not mention whether data is merged or replaced, whether nodesAccess is overwritten wholesale, what happens if the id does not exist, or whether any validation is performed. This is a significant gap for a write operation.
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 sentence with no filler. It front-loads the action and resource, then lists the updateable attributes. Every word 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?
There is no output schema and no annotations, and the tool involves a nested object and an array parameter. The description tells the agent what the tool does but not how updates behave (partial vs full replacement), what constraints apply, or what the result will look like. For a mutation tool, this is incomplete guidance.
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 the schema already documents each parameter. The description adds marginal value by summarizing the updateable fields, but it doesn't clarify the relationship between id and the other fields or the semantics of nodesAccess beyond what the schema says. Baseline 3 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') with a clear resource ('existing credential') and enumerates the exact updateable aspects (name, data, node access). This cleanly distinguishes it from create_credential, delete_credential, and test_credential without needing to open the schema.
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 phrase 'Update an existing credential' implies this is for modifying already-created credentials rather than creating or deleting them, but it does not explicitly name alternatives or state when not to use it. Sibling tools exist but are not referenced, so usage guidance is only implicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.