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 mentions 'options to control protocol and scope' but doesn't disclose behavioral traits like rate limits, authentication needs, data freshness, or what 'statistics' entail (e.g., counts, trends). The description is too vague to inform the agent adequately about how the tool behaves.

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 two sentences and front-loaded with the core purpose, but the second sentence about using the 'doc tool' is redundant if the schema is already provided, adding clutter without value. It's moderately concise but could be more streamlined.

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 no annotations, 0% schema coverage, no output schema, and 4 parameters, the description is incomplete. It lacks details on parameter usage, behavioral constraints, and output format, making it insufficient for the agent to use the tool effectively without external guidance.

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%, and the description doesn't add meaning for any parameters. It references 'protocol and scope' but doesn't explain what 'mode', 'protocol', or 'target' mean, their formats, or valid values. The agent is left guessing about parameter semantics beyond the bare schema.

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 states the tool provides backlink statistics for a URL/domain with date and protocol/scope options, which clarifies the verb (provides statistics) and resource (backlinks). However, it doesn't differentiate from sibling tools like 'site-explorer-all-backlinks' or 'site-explorer-refdomains', leaving ambiguity about what makes this tool unique.

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 includes 'Use doc tool first to get the real input schema', which provides a prerequisite but no guidance on when to use this tool versus alternatives. It doesn't specify scenarios, exclusions, or comparisons to sibling tools, leaving the agent without context for selection.

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