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Glama

Save Screenshot

mobile_save_screenshot

Capture a screenshot of a mobile device and save it to a file path for visual inspection or documentation.

Instructions

Save a screenshot of the mobile device to a file

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
scaleNoScale factor (0.0-1.0). Ignored if maxSize is provided.
deviceYesThe device identifier to use. Use mobile_list_available_devices to find which devices are available to you.
saveToYesThe path to save the screenshot to. Filename must end with .png, .jpg, or .jpeg
maxSizeNoMaximum width/height in pixels, keeping aspect ratio. Omit for full size.

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.0.1

TDQS

C2.9/5.0
Behavior3/5

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

Annotations declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the agent already knows this is a non-destructive local write. The description's addition that it saves to a file is consistent and mildly useful, but it says nothing about overwriting existing files, required permissions, or what is returned.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

A single short sentence with no filler; the action and destination are front-loaded. It is efficient, though arguably too terse to be maximally useful.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a four-parameter mutation tool with full schema coverage and no output schema, the description is adequate but thin: it omits sibling differentiation against mobile_take_screenshot and does not state whether the saved path is returned or whether existing files are overwritten.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all four parameters (scale, maxSize, device, saveTo) are fully documented in the schema, including the scale/maxSize interaction and the .png/.jpg/.jpeg filename requirement. The description adds no parameter detail beyond that, so the baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose3/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a clear verb and resource (save a screenshot to a file), which is more specific than the title. However, it never distinguishes itself from the sibling mobile_take_screenshot, leaving the agent to guess which one writes to disk versus returns image data.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no guidance on when to use this tool versus mobile_take_screenshot, nor any mention of prerequisites such as needing a device identifier. The only implied usage is the presence of a saveTo parameter.

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