n8n_list_credentials

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

With no annotations, the description fully covers behavioral traits: read-only, returns only metadata (no data field), requires admin/owner, defensive stripping of data field, and error behavior for unauthorized users. It does not discuss rate limits or side effects, but such details are unlikely needed. Transparency is good, so score 4.

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 (4 sentences) and front-loaded with the core action. It avoids redundancy, though the statement about defensive stripping slightly overlaps with the 'metadata only' claim. It is efficient but not maximally concise, earning a 4.

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 no output schema, the description adequately explains the return structure (each row). It covers authentication requirements, read-only nature, and defensive behavior. The tool is simple, and the description covers all necessary context for an agent to use it correctly. Score 5.

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% (both limit and cursor have clear descriptions). The tool description adds no additional meaning to the parameters beyond what the schema provides. Per guidelines, baseline is 3 when coverage is high, so a score of 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 clearly states it lists credentials and returns metadata only, with a detailed row structure. It distinguishes from sibling tools implicitly by specifying the resource, but does not explicitly contrast with other list tools like n8n_list_workflows. A score of 4 is appropriate for a clear, specific purpose with slight room for sibling differentiation.

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 clear context: read-only, requires admin/owner permissions, and mentions the 401 error for non-admin keys. However, it does not explicitly advise when to use this tool versus alternatives like n8n_get_credential_schema or n8n_find_workflows_using_credential. The guidance is solid but lacks explicit alternatives, warranting a 4.

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