LocatorLabs 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 that the tool returns 'all interactive elements with their best locators,' which gives some insight into output behavior. However, it doesn't cover critical aspects like whether this is a read-only operation, potential performance impacts (e.g., loading time for large pages), error handling, or authentication needs. For a tool with no annotations, this leaves significant gaps in understanding its behavior.

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 concise and well-structured with two sentences: the first states the core functionality, and the second provides usage context. Every sentence adds value without redundancy, making it easy to scan and understand quickly. It's appropriately sized for the tool's complexity.

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 moderate complexity (2 parameters, no output schema, no annotations), the description is minimally adequate. It covers the basic purpose and usage but lacks details on behavioral traits, output format, or error scenarios. Without annotations or an output schema, the description should do more to compensate, such as explaining what 'best locators' means or potential limitations. It meets a baseline but has clear gaps.

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 the schema already documents both parameters ('url' and 'elementTypes') with clear descriptions. The description doesn't add any meaningful semantic details beyond what the schema provides, such as examples of URL formats or explanations of 'best locators' in context. Baseline 3 is appropriate when the schema handles parameter documentation effectively.

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: 'Analyze an entire webpage and return all interactive elements with their best locators.' It specifies the verb (analyze), resource (webpage), and output (interactive elements with locators). However, it doesn't explicitly differentiate from sibling tools like 'get_locators' or 'generate_page_object,' which likely 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 some usage context: 'Use this to understand page structure or get all elements at once.' This implies when to use it (for comprehensive analysis) but doesn't explicitly state when not to use it or name alternatives among sibling tools. It offers basic guidance but lacks detailed comparisons or exclusions.

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