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 'filtering, field selection, and various scopes of analysis,' which hints at behavioral traits like configurability. However, it lacks critical details: whether this is a read-only operation, potential rate limits, authentication needs, data freshness, or what 'information' includes (e.g., metrics, lists). For a tool with 8 parameters and no annotations, this is insufficient.

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: the first states the purpose and features, the second is a technical note. It's front-loaded with the core functionality. However, the second sentence about using the 'doc tool' is arguably unnecessary clutter if the schema should be self-contained, slightly reducing efficiency.

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 high complexity (8 parameters, no schema descriptions, no annotations, no output schema), the description is incomplete. It doesn't explain return values, error conditions, or detailed usage scenarios. The mention of features like filtering is too vague to guide effective tool invocation, leaving significant gaps for an AI agent.

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 8 parameters have descriptions in the schema. The description only vaguely references 'filtering, field selection, and various scopes' without explaining specific parameters like 'mode', 'order_by', 'protocol', or 'where'. It fails to compensate for the lack of schema documentation, leaving parameters semantically unclear.

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 information about external domains that are linked from a specified target domain or URL.' It specifies the action (retrieves), resource (information about external domains), and scope (linked from target). However, it doesn't explicitly differentiate from sibling tools like 'site-explorer-outlinks-stats' or 'site-explorer-refdomains', which may 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 guidance: 'Use doc tool first to get the real input schema.' This is a technical prerequisite but doesn't explain when to use this tool versus alternatives (e.g., vs. 'site-explorer-outlinks-stats' for outlink statistics or 'site-explorer-refdomains' for referring domains). No explicit when/when-not or alternative tool recommendations are included.

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