MCP Appium Server

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

With no annotations provided, the description carries full burden but only states the basic function. It doesn't disclose behavioral traits like whether this is a read-only operation (implied but not stated), if it returns a boolean or detailed result, error handling (e.g., invalid selector), performance characteristics, or dependencies (e.g., requires Appium session). For a tool with zero annotation coverage, 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 a single, direct sentence with zero wasted words. It's front-loaded with the core purpose and efficiently communicates the essential action. Every word earns its place, making it highly scannable and easy to parse.

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 (checking element existence in a UI automation context), no annotations, no output schema, and rich sibling tools, the description is incomplete. It lacks context on return values (e.g., boolean vs. element details), error conditions, typical workflows, and differentiation from similar tools. This leaves significant gaps 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 100%, with both parameters ('selector' and 'strategy') well-documented in the schema. The description adds no parameter-specific information beyond what the schema provides, such as examples of common selectors or when to choose different strategies. This meets the baseline for high schema coverage but doesn't enhance understanding.

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 verb ('Check if') and resource ('an element exists on the current page'), making the purpose immediately understandable. It doesn't explicitly differentiate from siblings like 'find-by-text' or 'wait-for-element', but the checking vs. finding distinction is somewhat implied. This is clear but lacks explicit sibling differentiation.

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 no guidance on when to use this tool versus alternatives like 'find-by-text', 'wait-for-element', or 'inspect-element'. It doesn't mention prerequisites (e.g., requires an active page/session) or typical use cases (e.g., validation before interaction). This leaves the agent with minimal context for tool selection.

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