Read messages visible to an agent—direct, broadcast, and its own—and mark them read unless disabled. Use it to check inbox activity and manage unread communications.
Read messages visible to this agent (direct, broadcast, and its own). Marks them read unless markRead=false.
| Name | Required | Description | Default |
|---|---|---|---|
| agent | Yes | ||
| limit | No | ||
| markRead | No | ||
| unreadOnly | No |
Changes observed during successful MCP inspections.
v0.5.11Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It does disclose the key side effect that messages are marked read unless markRead=false, which is the most important mutation to flag. It does not mention pagination, ordering, default limit behavior, or what happens when unreadOnly and markRead interact.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
A single tight sentence with the scope front-loaded and the side effect trailing. Nothing is wasted, though the density means two distinct concepts (visibility scope and read-marking) are packed without separation.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a 4-parameter read tool with no annotations and no output schema, the description covers purpose and the destructive-adjacent markRead behavior but leaves limit, unreadOnly, and the return shape unexplained. An agent can call it, but cannot predict ordering or page boundaries.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must compensate, and it does explain the two most consequential parameters: agent scope (visible to this agent) and markRead (with its false escape hatch). limit and unreadOnly are left entirely to the bare schema types and defaults, so the coverage is partial rather than complete.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb+resource (read messages) and enumerates the visibility scope: direct, broadcast, and its own. This distinguishes it from write-side siblings like bus_send and search-side siblings like bus_search, though it never names those alternatives explicitly.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The parenthetical scope note implies when this tool is appropriate (checking what has arrived for an agent), but there is no explicit when-not guidance, no mention of bus_search or bus_events as alternatives, and no prerequisites such as registration or token state.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.