tools_documentation

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

Annotations already declare readOnlyHint=true and idempotentHint=true, so the agent knows this is a safe, read-only operation. The description adds behavioral context beyond annotations: it explains that calling without parameters returns a 'quick start guide,' and that depth='full' provides 'comprehensive documentation.' This clarifies the different response modes. No contradictions with annotations.

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 three sentences, each adding value: first sentence states the core purpose, second gives the default behavior, third explains the two optional parameters. It is front-loaded and contains no unnecessary words. Every sentence 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?

Given the tool's simplicity (2 optional params, no output schema), the description covers the main use cases well. It explains all invocation modes. However, it does not describe the format of the returned documentation (e.g., markdown, text), which would be helpful for an agent. Still, it is largely complete for a straightforward documentation tool.

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 mentions using the 'topic' parameter and 'depth="full"', but this mostly restates the schema's own descriptions. It adds minimal new meaning beyond what the schema already provides. Therefore, 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 the tool's purpose: 'Get documentation for n8n MCP tools.' It distinguishes itself from siblings (which deal with templates, nodes, validation) by explicitly focusing on tool documentation. The different invocation modes (no params, topic, depth) are also outlined, making the purpose very specific.

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 explicit usage guidance: 'Call without parameters for quick start guide. Use topic parameter to get documentation for specific tools. Use depth="full" for comprehensive documentation.' This tells the agent exactly when to use each parameter combination. It does not mention when not to use the tool or alternatives, but the sibling tools are sufficiently different that no further exclusion is needed.

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