Ahrefs MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It mentions 'extensive support for filtering, sorting, and metric selection' and implies retrieval of SEO metrics, but lacks critical details: it doesn't specify whether this is a read-only operation, potential rate limits, authentication requirements, or what happens on errors. For a tool with 10 parameters and no annotation coverage, this is a significant gap in transparency.

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 moderately 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 a purpose-focused description. The first sentence is front-loaded with the core purpose, but could be more streamlined by integrating the filtering/sorting details more 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 complexity (10 parameters, 0% schema coverage, no annotations, no output schema), the description is incomplete. It outlines the basic purpose but misses essential context: no details on parameter usage, behavioral traits like safety or performance, output format, or error handling. For a data retrieval tool with many configuration options, this leaves too much ambiguity for effective agent use.

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%, so the description must compensate for all 10 parameters. It only vaguely references 'filtering, sorting, and metric selection' and 'matching input terms or phrases,' which partially hints at parameters like 'where', 'order_by', 'select', 'terms', or 'keywords'. However, it fails to explain specific parameters such as 'country', 'limit', 'match_mode', 'timeout', or 'keyword_list_id', leaving most semantics undocumented.

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 keyword ideas and their associated SEO metrics by matching input terms or phrases in a specified country.' It specifies the verb ('retrieves'), resource ('keyword ideas and their associated SEO metrics'), and key constraints ('matching input terms or phrases in a specified country'). However, it doesn't explicitly differentiate from sibling tools like 'keywords-explorer-related-terms' or 'keywords-explorer-search-suggestions', which likely serve similar purposes in the same domain.

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 'extensive support for filtering, sorting, and metric selection,' which hints at when to use it for detailed analysis, but offers no explicit when-to-use or when-not-to-use advice. The instruction 'Use doc tool first to get the real input schema' is procedural rather than contextual, failing to guide selection among alternatives like 'keywords-explorer-overview' or 'keywords-explorer-volume-by-country'.

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