google-slides-mcp

diff_pages

Compare two slides pixel-by-pixel to identify visual differences. Returns a normalized mismatch ratio and a diff image showing changed regions.

Instructions

Render two slides and report their pixel difference. (2 expensive calls.)

Renders both pages, computes a normalized mismatch ratio in [0, 1] (0 = pixel identical), and returns a visual diff image highlighting changed regions. Useful to verify a duplicated/edited slide matches the showcase original.

Returns a text summary followed by the diff PNG.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "presentation_id": "<presentation_id>",
      "page_a": "<page_a>",
      "page_b": "<page_b>"
    },
    "name": "diff_pages"
  }
}

Input Schema

Name	Required	Description	Default
`presentation_id`	Yes
`page_a`	Yes
`page_b`	Yes
`size`	No	LARGE, MEDIUM, or SMALL	MEDIUM

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jun 23, 2026

TDQS

A4.1/5.0

Behavior4/5

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

No annotations are provided, so the description carries full burden. It discloses the performance cost (2 expensive calls), the output format (normalized mismatch ratio and diff image), and the order of return (text summary then PNG). This is comprehensive, though it could mention idempotency or 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.

Conciseness5/5

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

The description is four sentences, each earning its place: main action, cost, output detail, and use case. It is front-loaded with the core behavior and avoids unnecessary verbosity.

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

Completeness4/5

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

Given the presence of an output schema (which covers return values) and sibling tools, the description provides sufficient behavioral and use-case context. It lacks parameter format details but is otherwise complete for a comparison tool with moderate complexity.

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

Parameters2/5

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

Schema description coverage is only 25% (only 'size' has a description). The description does not add meaning for the three required parameters (presentation_id, page_a, page_b). It implies page identifiers are slide IDs but does not clarify format or constraints, leaving a significant gap for agent use.

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

Purpose5/5

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

The description starts with 'Render two slides and report their pixel difference,' clearly stating the verb and resource. It distinguishes from sibling render_page (single slide rendering) and mentions a specific use case (verifying duplicated/edited slides), providing strong purpose clarity.

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

Usage Guidelines4/5

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

The description notes '(2 expensive calls)' to indicate cost and suggests usage for verifying slide matches. While it does not explicitly list when not to use or name alternatives, the context is clear and helpful for making an informed choice.

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