mcp-server-mattermost

create_bookmark

Add a link or file bookmark to a Mattermost channel by providing the channel ID, display name, and bookmark type. Create link bookmarks with a URL or file bookmarks with an uploaded file ID to organize important resources.

Instructions

Create a channel bookmark.

Creates a link bookmark (URL) or file bookmark (attached file). For link type, link_url is required. For file type, file_id is required (from upload_file).

Note: Requires Entry, Professional, Enterprise, or Enterprise Advanced edition (not available in Team Edition). Minimum version: v10.1.

Input Schema

TableJSON Schema

Name	Required	Description
`emoji`	No	Emoji icon
`file_id`	No	File ID (required for file type)
`link_url`	No	URL (required for link type)
`image_url`	No	Preview image URL
`channel_id`	Yes	26-character channel identifier (e.g., 'o5w8h47pdfbzjc4d8w7dhnhren')
`display_name`	Yes	Bookmark display name
`bookmark_type`	Yes	Bookmark type: 'link' or 'file'

Output Schema

TableJSON Schema

Name	Required	Description
`id`	Yes	Unique bookmark identifier
`file`	No	File metadata for file bookmarks
`type`	Yes	Bookmark type: 'link' or 'file'
`emoji`	No	Emoji icon
`file_id`	Yes	File ID for file bookmarks (empty for links)
`link_url`	No	URL for link bookmarks
`owner_id`	Yes	User ID who created the bookmark
`create_at`	Yes	Creation timestamp in milliseconds
`delete_at`	Yes	Deletion timestamp (0 if not deleted)
`image_url`	No	Preview image URL
`parent_id`	No	Parent bookmark ID
`update_at`	Yes	Last update timestamp in milliseconds
`channel_id`	Yes	Channel this bookmark belongs to
`sort_order`	Yes	Position in bookmark list
`original_id`	No	Original bookmark ID if copied
`display_name`	Yes	Bookmark display name

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv0.6.1Sep 10, 2026

addedOutput schema / properties / file

Added value: +{
+  "anyOf": [
+    {
+      "additionalProperties": true,
+      "description": "Uploaded file metadata.\n\nNote: Go source uses CreatorId field name, but JSON response uses \"user_id\".\n\nSee: https://github.com/mattermost/mattermost/blob/master/server/public/model/file_info.go",
+      "properties": {
+        "channel_id": {
+          "description": "Channel where file was uploaded",
+          "type": "string"
+        },
+        "create_at": {
+          "description": "Upload timestamp in milliseconds",
+          "type": "integer"
+        },
+        "delete_at": {
+          "description": "Deletion timestamp",
+          "type": "integer"
+        },
+        "extension": {
+          "description": "File extension without dot",
+          "type": "string"
+        },
+        "has_preview_image": {
+          "default": false,
+          "description": "Has generated preview",
+          "type": "boolean"
+        },
+        "height": {
+          "default": 0,
+          "description": "Image height in pixels",
+          "type": "integer"
+        },
+        "id": {
+          "description": "Unique file identifier",
+          "type": "string"
+        },
+        "mime_type": {
+          "description": "MIME type",
+          "type": "string"
+        },
+        "name": {
+          "description": "File name",
+          "type": "string"
+        },
+        "post_id": {
+          "default": "",
+          "description": "Associated post ID",
+          "type": "string"
+        },
+        "size": {
+          "description": "File size in bytes",
+          "type": "integer"
+        },
+        "update_at": {
+          "description": "Last update timestamp",
+          "type": "integer"
+        },
+        "user_id": {
+          "description": "Uploader user identifier (CreatorId in Go)",
+          "type": "string"
+        },
+        "width": {
+          "default": 0,
+          "description": "Image width in pixels",
+          "type": "integer"
+        }
+      },
+      "required": [
+        "id",
+        "user_id",
+        "channel_id",
+        "create_at",
+        "update_at",
+        "delete_at",
+        "name",
+        "extension",
+        "size",
+        "mime_type"
+      ],
+      "type": "object"
+    },
+    {
+      "type": "null"
+    }
+  ],
+  "default": null,
+  "description": "File metadata for file bookmarks"
+}

removedOutput schema / properties / file_info

Removed value: -{
-  "anyOf": [
-    {
-      "additionalProperties": true,
-      "type": "object"
-    },
-    {
-      "type": "null"
-    }
-  ],
-  "default": null,
-  "description": "File metadata for file bookmarks"
-}

First observedv0.5.1Jul 29, 2026

TDQS

A3.9/5.0

Behavior3/5

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

The description reveals the action's preconditions (edition, version, required fields) but doesn't state side effects, return values, or permission requirements. Since no readOnly annotation is present崗, the description carries the burden for mutation transparency and only partially covers it.

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?

Concise, front-loaded with the core purpose, then conditional rules, then constraints. No filler or redundancy.

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?

Covers the essential invocation conditions and edition/version constraints. Lacks explicit output/return details and permission requirements, but the schema and existing sibling context cover basic usage.

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?

Input schema already documents all parameters (100% coverage). The description adds conditional-requirement meaning by linking bookmark_type to link_url and file_id, and references upload_file as the source for file_id, which goes beyond the schema descriptions.

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

Purpose4/5

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

The description clearly identifies the action ('Create a channel bookmark') and the resource (bookmark), and distinguishes two subtypes (link vs file). It doesn't explicitly contrast with sibling list/update/delete tools, but the purpose is unambiguous.

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?

Provides clear conditional usage: link type requires link_url, file type requires file_id from upload_file. Also specifies edition and version constraints, which serve as prerequisites. Doesn't state alternatives or when not to use this tool, but the conditions are actionable.

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