MCP-Midscene

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 scrolling behavior but lacks critical details: it doesn't specify what happens if scrolling fails, whether it waits for page loads, if it's idempotent, or any performance/rate limit considerations. This is inadequate for a tool with 5 parameters and potential side effects.

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 perfectly concise - two sentences that efficiently cover the core functionality without any redundant information. It's front-loaded with the primary purpose and follows with the key behavioral distinction.

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?

For a tool with 5 parameters, no annotations, and no output schema, the description is insufficient. It doesn't explain what the tool returns, error conditions, or how it interacts with the page state. Given the complexity and lack of structured metadata, more behavioral context is needed.

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 all parameters thoroughly. The description adds minimal value beyond the schema - it mentions 'page or a specified element' which relates to the 'locate' parameter, but doesn't provide additional context about parameter interactions or edge cases.

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 function ('Scrolls the page or a specified element') and distinguishes between two scrolling modes ('by a fixed amount or until an edge is reached'). It uses specific verbs and identifies the resource, though it doesn't explicitly differentiate from sibling tools like navigation or tab management.

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. It doesn't mention sibling tools like 'midscene_navigate' for page navigation or 'midscene_aiHover' for element interaction, leaving the agent without 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.