list_credentials

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

With no annotations, the description carries the behavioral disclosure burden. It does reasonably well: 'List' signals a non-mutating operation and the parenthetical reveals an important implementation trait—credentials are combined from workflows and a database fallback. It stops short of describing edge cases or output shape, but the core behavior is transparent.

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?

A single dense sentence, front-loaded with the verb and resource, with the clarifying sourcing detail in parentheses. No filler or redundancy.

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 low-complexity list tool with one optional parameter and no output schema, the description is nearly complete: it states scope, source, and default behavior. It would only need explicit output/return details or failure semantics to be fully complete.

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%, and the only parameter (type) is already documented as an optional filter with an example. The tool description adds no extra parameter meaning beyond its 'all credentials' default, so baseline 3 applies.

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 names a specific operation ('List') and a clear resource ('all credentials available in n8n'), and adds a useful provenance detail ('parsed from workflows + database fallback'). This distinguishes it from sibling tools like get_credential_schema, create_credential, or 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?

It clearly indicates this is for enumerating credentials, giving context that this is the listing entry point. It does not explicitly name alternatives or exclusion cases, but the read-only listing intent is unambiguous and no conflicting sibling does the same thing.

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