get_scroll_positionRetrieve scroll position, document dimensions, and viewport size to compute scroll_by deltas for navigation.
Returns the current scroll position of the session page plus document scroll dimensions and the viewport size — useful for planning further scroll_by deltas.
| Name | Required | Description | Default |
|---|---|---|---|
| sessionId | Yes | Session id returned by start_session. Required on every stateful tool call. |
Changes observed during successful MCP inspections.
v1.0.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the burden. It discloses that the tool returns scroll position, document scroll dimensions, and viewport size, which is helpful. However, it doesn't mention whether this is a read-only operation, any side effects, or what the exact return shape is. Since it's a getter, the read-only nature is implied but not explicit.
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?
One sentence, front-loaded with the main purpose, and the use-case hint is appended. No wasted words.
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 simple getter with one parameter and no output schema, the description is mostly complete. It could mention that the return values are in pixels or that it's read-only, but the core information an agent needs to call it correctly is present.
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 the sessionId parameter. The description doesn't add any parameter-specific meaning beyond what the schema provides, which is fine given the high coverage.
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 states a specific verb ('Returns') and resource ('current scroll position of the session page') and adds the extra dimensions and viewport size. It clearly distinguishes itself from get_viewport_size and scroll_by, which are siblings.
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 says it is 'useful for planning further scroll_by deltas', which gives clear context for when to use it. It doesn't explicitly mention when not to use it or name alternatives like get_viewport_size, but the context is clear enough.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.