tools_documentation

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

Annotations declare readOnlyHint=true and idempotentHint=true, so the safety profile is covered. The description adds parameter-dependent behavior contexts (quick start vs specific tool docs vs comprehensive docs), which is useful. However, it does not disclose additional behavioral details like output format, pagination, or error handling, but for a documentation tool these are less critical. The description does not contradict annotations, and the added context is modest.

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, with the purpose stated in the first sentence and usage instructions in the next two. Every sentence provides essential information, with no waste or redundancy. It is appropriately front-loaded and efficiently communicates the core functionality and options.

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 (no required params, no output schema), the description is nearly complete. It covers all usage modes (no params, topic, depth) and mentions the quick start guide. The only minor gap is not describing the output format (e.g., markdown vs plain text), but for a documentation tool this is not a significant omission. Overall it is sufficiently complete for an agent to select and invoke correctly.

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%, with both depth and topic already described in detail (e.g., depth enum values and topic examples). The description repeats similar guidance ('Use depth="full" for comprehensive documentation' mirrors the schema's 'full' meaning). It adds minimal extra meaning beyond the schema, so the baseline 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 function: 'Get documentation for n8n MCP tools.' This specifies the verb (Get) and resource (documentation for MCP tools), and distinguishes from siblings like get_node or search_nodes which operate on actual data, not documentation. The mention of a quick start guide and depth levels further clarifies scope.

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 gives explicit usage scenarios: 'Call without parameters for quick start guide', 'Use topic parameter to get documentation for specific tools', and 'Use depth="full" for comprehensive documentation.' This provides clear context for when to use different parameter combinations. It doesn't explicitly state exclusions or alternatives, but the guidance is strong enough to make the tool's usage obvious.

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