Previews

update_preview

Deploy a new version to an existing preview slug to iterate on a prototype while preserving its version history.

Instructions

Deploy a new version to an existing preview slug. Automatically iterates on the existing prototype while preserving version history.

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": {
      "slug": "<slug>",
      "files": "<files>"
    },
    "name": "update_preview"
  }
}

Input Schema

Name	Required	Description
`slug`	Yes	The existing preview slug to update
`files`	Yes	Array of files to add or replace.
`changelog`	No	Brief description of changes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.4.0Nov 6, 2026

TDQS

A3.7/5.0

Behavior3/5

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

With no annotations, the description carries the full burden of behavioral disclosure. It usefully states that it deploys a new version, automatically iterates on the existing prototype, and preserves version history, but it does not cover permissions/auth requirements, reversibility, how files not listed are handled, or what the response contains.

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 two concise sentences with the core action front-loaded. Every phrase adds useful information about the update target and version-history behavior, with no wasted wording.

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?

The description is adequate for a moderate-complexity mutation tool with fully documented parameters, but it omits important context such as auth requirements and update semantics for files not included in the request. It also provides no return-value information despite having no output schema.

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 the input schema already documents slug, files, and changelog. The description does not add parameter-level meaning beyond what the schema provides, so the baseline score of 3 is appropriate.

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 states a specific verb and resource: deploying a new version to an existing preview slug. The phrase 'existing preview slug' distinguishes it from create_preview, which would create a new preview, and from list/get/delete siblings. It also adds the outcome of iterating on the prototype while preserving version history.

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

Usage Guidelines3/5

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

Usage is implied by 'existing preview slug', which tells the agent this is for updating an already-created preview rather than creating a new one. However, it does not explicitly say when to choose this over create_preview or other alternatives, nor does it state exclusions or prerequisites.

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

Deploy Server