Ahrefs MCP Server

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

No annotations are provided, so the description carries full burden. It states the tool provides 'full documentation' and input schemas, which implies a read-only, non-destructive behavior. However, it lacks details on authentication needs, rate limits, error handling, or output format. For a tool with no annotations, this is a moderate gap in behavioral disclosure.

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 and front-loaded: two sentences with zero wasted words. The first sentence states the overall purpose, and the second provides critical usage instructions. Every sentence earns its place by delivering essential information efficiently.

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 low complexity (one optional parameter, no output schema, no annotations), the description is reasonably complete. It covers purpose and usage well but lacks details on behavioral aspects like authentication or error handling. For a documentation-retrieval tool, this is sufficient though not exhaustive.

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 input schema has 100% description coverage for its single parameter ('tool'), documented as 'The name of the tool.' The description adds context by explaining this parameter is used to 'get the input schema for any other tool,' clarifying its purpose beyond the schema's basic type information. With high schema coverage and only one parameter, this provides adequate semantic value.

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: 'Full documentation for Ahrefs tools' specifies it provides comprehensive documentation, and 'You must use this tool to get the input schema for any other tool' explicitly defines its function as retrieving input schemas for sibling tools. This distinguishes it from all listed siblings, which perform data analysis or management tasks rather than documentation retrieval.

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: 'You must use this tool to get the input schema for any other tool' directly instructs when to use it (before invoking other tools) and implies when not to use it (for actual data operations). This clearly differentiates it from all sibling tools, which are for executing operations rather than schema discovery.

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