snapdiff-mcp

snapdiff_check_build

Capture multiple pages and diff them against baselines in one build to detect unintended changes from shared component edits. Returns a per-page summary and a review URL for any changed pages.

Instructions

Capture every page in the list and diff them all against their baselines in one build. Use this after editing a shared component or design token to check whether the change affected pages you did not directly modify.

Returns a per-page summary of changed vs unchanged. If any page changed, a review URL is included so a human can approve or reject before the baseline moves.

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": {
      "project": "<project>",
      "pages": "<pages>"
    },
    "name": "snapdiff_check_build"
  }
}

Input Schema

Name	Required	Description
`project`	Yes	Project slug or ID (prj_xxx).
`pages`	Yes	Pages to capture and diff. Pass every route in your page map.
`branch`	No	Branch to look up baselines on. Defaults to the project's default branch.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.4.2Jun 17, 2026

TDQS

A4.4/5.0

Behavior4/5

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

Since no annotations are provided, the description carries the full burden of behavioral disclosure. It explains the tool captures pages, diffs against baselines, returns a per-page summary, and includes a review URL if changes are detected. It also notes that localhost URLs are captured locally without a tunnel. This adequately informs the agent about the tool's behavior without contradictions.

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 concise with no wasted words. It consists of two short paragraphs: the first defines the action and use case, the second describes the output. Every sentence adds value, and the structure is easy to parse.

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 tool has 3 parameters and no output schema, the description does a good job covering essential aspects: the batch nature, the return format (per-page summary), and the inclusion of a review URL. It also addresses the niche case of localhost. However, it does not explain what 'baselines' are or how to interpret the summary, but this is likely common knowledge in the domain.

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

Parameters4/5

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

Although schema description coverage is 100%, the description adds meaningful context beyond the schema. It advises to 'Pass every route in your page map' for the pages parameter and clarifies that localhost URLs are handled without a tunnel. This helps the agent understand the intended usage beyond the raw parameter descriptions.

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 clearly states 'Capture every page in the list and diff them all against their baselines in one build.' It uses a specific verb ('capture' and 'diff') and identifies the resource (pages in a project). The phrase 'in one build' distinguishes it from sibling tools like snapdiff_compare_pages, which likely handles individual comparisons.

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 provides explicit guidance: 'Use this after editing a shared component or design token to check whether the change affected pages you did not directly modify.' This tells the agent when to use the tool and implies that for single-page changes, a different tool might be more appropriate. However, it does not explicitly list alternatives or situations to avoid.

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

Deploy Server