Ahrefs MCP Server

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 'retrieves' (implying a read operation) and 'flexible filtering, selection, and sorting', but lacks details on permissions, rate limits, pagination, error handling, or what the output looks like. For a tool with 9 parameters and no annotations, this leaves significant behavioral gaps, though it does hint at some capabilities like filtering and sorting.

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 relatively concise with two sentences, but the second sentence 'Use doc tool first to get the real input schema' is procedural clutter that doesn't belong in the description—it should be in documentation or tool metadata. The first sentence is informative but could be more front-loaded with key details. Overall, it's somewhat efficient but includes unnecessary elements.

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 complexity (9 parameters, no annotations, no output schema), the description is incomplete. It doesn't explain the return values, error conditions, or detailed parameter usage. While it states the purpose, it lacks sufficient context for an agent to use the tool effectively without external documentation. The instruction to use another tool for schema details highlights this inadequacy.

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 0%, meaning none of the 9 parameters have descriptions in the schema. The description vaguely mentions 'flexible filtering, selection, and sorting' but doesn't explain what parameters like 'history', 'mode', 'order_by', 'protocol', 'select', 'target', 'timeout', or 'where' actually mean or how to use them. It fails to compensate for the lack of schema documentation, leaving parameters largely unexplained.

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: 'Retrieves detailed information about referring domains that link to a specified target domain or URL.' It specifies the verb ('retrieves'), resource ('referring domains'), and scope ('link to a specified target domain or URL'), making it clear what the tool does. However, it doesn't explicitly differentiate from sibling tools like 'site-explorer-linkeddomains' or 'site-explorer-all-backlinks', which might have overlapping functionality.

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 minimal usage guidance. It mentions 'flexible filtering, selection, and sorting of backlink-related metrics' but doesn't specify when to use this tool versus alternatives like 'site-explorer-linkeddomains' or 'site-explorer-all-backlinks'. The instruction 'Use doc tool first to get the real input schema' is procedural rather than contextual guidance on tool selection. No explicit when/when-not scenarios or prerequisites are provided.

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