n8n-mcp

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It mentions the requirement for 'write_mode', which is useful context about permissions. However, it lacks details on other behavioral traits: it doesn't specify if the creation is idempotent, what happens on duplicate names, the response format (though an output schema exists), or any rate limits. For a mutation tool with zero annotation coverage, this is a significant gap.

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 extremely concise with two short sentences, front-loading the main action ('Create a new tag') and following with a critical requirement ('Requires write_mode'). There is zero waste, and every sentence adds value, making it efficient and easy to parse.

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 complexity (a simple creation operation with one parameter), the description covers the basic purpose and a key requirement. However, with no annotations and an output schema present, it lacks details on behavioral aspects like error handling or idempotency. The description is minimal but adequate for the context, though it could be more complete by addressing potential issues like duplicates.

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?

The description does not mention any parameters, and schema description coverage is 0%, so the schema alone documents the 'name' parameter. The description adds no semantic information about the parameter, such as format constraints or examples. With only one parameter and no schema descriptions, the baseline is 3, as the schema provides the basic structure but the description doesn't compensate for the lack of coverage.

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 ('Create') and resource ('a new tag'), making the purpose immediately understandable. It distinguishes from sibling tools like 'delete_tag', 'update_tag', and 'list_tags' by specifying creation rather than other operations. However, it doesn't specify what a 'tag' is in this context, which could help differentiate from other creation tools like 'create_credential' or '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 states 'Requires write_mode', providing clear context about when to use this tool (when in write mode). It implies usage for creating new tags, distinguishing from 'update_tag' for modifications or 'list_tags' for viewing. However, it doesn't specify alternatives or exclusions, such as when not to use it or what happens if a tag with the same name exists.

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