1Password MCP Server

password_update

Rotate or update a password or concealed field on a 1Password item, creating the field if it doesn't exist.

Instructions

Update (rotate) a password or concealed field on an existing 1Password item. If the target field does not exist, it will be created.

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": {
      "vaultId": "<vaultId>",
      "itemId": "<itemId>",
      "newPassword": "<newPassword>"
    },
    "name": "password_update"
  }
}

Input Schema

Name	Required	Description
`field`	No	Field id or title to update. Defaults to 'password'.
`itemId`	Yes	Item ID to update.
`vaultId`	Yes	Vault ID containing the item.
`newPassword`	Yes	New password value.
`returnSecret`	No	If true, include the updated password in the response. Defaults to false for security.

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv4.0.1Jul 31, 2026

changedInput schema / $schema

Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"

removedInput schema / additionalProperties
```
Removed value: -false
```

First observedv2.4.2Jun 21, 2026

TDQS

A3.9/5.0

Behavior3/5

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

Without annotations, the description carries the full burden. It discloses one behavioral trait: if the target field does not exist, it will be created. However, it does not mention permissions, reversibility, side effects, or what happens to the item's metadata, which are important for a mutation tool.

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 sentences, with the main action stated first and the key side-effect in the second sentence. Every word contributes value; there is no fluff or repetition.

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?

This is a mutation tool with no output schema and no annotations. The description covers the core action and creation behavior, but it does not explain return values or clarify when to choose this over sibling item_edit, which could also modify fields. Given the low complexity, a 3 is appropriate.

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 baseline is 3. The description adds no extra parameter semantics beyond what the schema already provides, but since the schema is thorough, the description does not need to compensate.

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 uses a specific verb 'Update (rotate)' and clearly identifies the resource: a password or concealed field on an existing 1Password item. This distinguishes it from sibling tools like password_create (which creates new items) and password_read (which reads values).

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 clear context by stating it applies to 'an existing 1Password item,' implying it is not for creation. However, it does not explicitly mention alternatives or when-not-to-use scenarios, so it falls slightly short of a 5.

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

Deploy Server