Read messages from a conversation thread. Use text_contains to find specific messages by content. Returns the most recent messages, including sender info and timestamps. Voice calls: each row carries a meta object with allowlisted keys (event_type ∈ 'call_started'|'call_ended'|null, source ∈ 'voi...
Risk signalsBulk/mass operation — affects multiple targets
Part of the Dialogbrain server.
Free to start. No card required.
AI agents call messages_read_history to retrieve information from Dialogbrain without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though messages_read_history only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"messages_read_history": {}
}
}See the full Dialogbrain policy for all 157 tools.
These attack patterns abuse exactly the kind of access messages_read_history gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Read messages from a conversation thread. Use text_contains to find specific messages by content. Returns the most recent messages, including sender info and timestamps. Voice calls: each row carries a meta object with allowlisted keys (event_type ∈ 'call_started'|'call_ended'|null, source ∈ 'voice_transcript'|null, call_id, speaker_display_name, duration_seconds, outcome, direction) plus per-message channel. To find calls without scanning every row, use calls.list_history instead. Usage: 1. Get thread_id from threads.list first, OR 2. Use contact_name to auto-resolve thread_id Examples: - User: 'show me messages from chat with [contact]' → read_history(contact_name='[contact]', limit=10) - User: 'last 5 messages from thread 571' → read_history(thread_id=571, limit=5). It is categorised as a Read tool in the Dialogbrain MCP Server, which means it retrieves data without modifying state.
Register the Dialogbrain MCP server in PolicyLayer and add a rule for messages_read_history: 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.
messages_read_history 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 messages_read_history 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 messages_read_history. 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.
messages_read_history 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.
Deterministic rules across all 157 Dialogbrain tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
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