group_preview_messages
Read recent public messages from a group without joining it. Only works for groups where can_preview_history=true. Use this to manually evaluate message quality before deciding to join. For an automated quality score, use group.scan instead. Returns: list of recent messages with sender identity (...
This record as markdown: /tools/io-github-saloprj-dialogbrain/group-preview-messages.md
What group_preview_messages does on Dialogbrain
AI agents call group_preview_messages to retrieve information from Dialogbrain without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
limit | integer | — | Number of recent messages to fetch (1-100, default 20) |
group_id | integer | Yes | ID of the discovered group (from group.search or group.list) |
full_text | boolean | — | Return untruncated message text. OMIT for 150-char previews (keeps large batches consumable). |
Parameters from the server's own tool schema.
Why group_preview_messages is rated Low
This tool only retrieves and displays message data from groups that have explicitly enabled preview functionality (can_preview_history=true). It is a read-only operation with no side effects, making it a Read category risk.
From the tool's definition Tool description explicitly states 'Read recent public messages from a group' and returns 'list of recent messages' with metadata. No modifications, deletions, or external operations are performed.
Risk signalsAdmin/system-level operation
Attacks that exploit this kind of access
The rule that runs group_preview_messages safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Dialogbrain, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For group_preview_messages, this is the rule to start with:
group_preview_messages is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Dialogbrain, apply this rule, and every group_preview_messages call is checked against it from then on.
Questions about group_preview_messages
Read recent public messages from a group without joining it. Only works for groups where can_preview_history=true. Use this to manually evaluate message quality before deciding to join. For an automated quality score, use group.scan instead. Returns: list of recent messages with sender identity (username, name, admin flag), text (150-char previews; pass full_text=true for untruncated), date, is_reply. It is categorised as a Read tool in the Dialogbrain MCP Server, which means it retrieves data without modifying state.
group_preview_messages accepts 3 parameters: limit, group_id, full_text. Required: group_id. The full parameter table on this page comes from the server's own tool schema.
Register the Dialogbrain MCP server in PolicyLayer and add a rule for group_preview_messages: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Dialogbrain. Nothing to install.
group_preview_messages is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the group_preview_messages rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for group_preview_messages. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
group_preview_messages is provided by the Dialogbrain MCP server (https://api.dialogbrain.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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