n8n_manage_credentials

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

Annotations already indicate read/write capability. The description adds a valuable behavioral note: 'credential data values are never logged', enhancing security transparency. No contradictions; the description builds on annotations without repeating structure.

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 two sentences with no fluff. It front-loads the action list and closes with a critical security note. Every sentence serves a purpose.

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?

For a multi-action CRUD tool, the description covers the essential purpose, available actions, and a key security behavior. It lacks details on return values or error conditions, but these are partially covered by the schema and annotations, making it sufficient for the complexity level.

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 baseline is 3. The description adds a workflow hint about using getSchema, but does not explain parameter semantics beyond what the schema provides. It is adequate but not additive.

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 tool manages n8n credentials and enumerates all six actions (list, get, create, update, delete, getSchema). It uses a specific verb-resource combination and is easily distinguished from sibling tools like n8n_create_workflow.

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 explicitly advises using getSchema before create to discover required fields, providing a clear usage hint. However, it does not specify when not to use this tool or compare it to alternatives, leaving implicit the full decision context.

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