Serpstat MCP Server

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

With no annotations provided, the description carries full burden and excels by disclosing critical behavioral traits: high cost (1000-2000 credits), explicit confirmation requirement, API cost breakdown (1000 credits per metric), and aggregation behavior ('aggregates statistics' for URLs matching pattern). This goes well beyond basic functionality.

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 appropriately sized and front-loaded with core functionality, though it could be slightly more concise. Every sentence earns its place: first states purpose, second explains scope, third highlights cost warning, fourth provides user confirmation instructions, and fifth details API costs.

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 complexity (costly API operation with 4 parameters), no annotations, and no output schema, the description provides excellent contextual completeness. It covers purpose, behavioral constraints, cost implications, parameter guidance, and distinguishes the tool's specific use case within the sibling tool ecosystem.

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 100%, so baseline is 3. The description adds value by explaining the urlContains parameter's aggregation behavior ('Method finds all URLs containing this substring and aggregates statistics') and providing usage guidance for output_data parameter, elevating the score above baseline.

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 with specific verbs ('Returns traffic and keyword statistics') and resources ('website pages that match a specific URL mask'), and distinguishes it from siblings by focusing on URL-based aggregation rather than domain-wide or keyword-specific analysis seen in tools like get_domain_keywords or get_url_keywords.

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 guidelines by warning 'HIGH-COST METHOD - EXPLICIT CONFIRMATION REQUIRED' and specifying when to use alternatives through the output_data parameter explanation: 'If not specified, returns both traffic and keywords (2000 credits). Specify this parameter unless both metrics are required.'

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