Blocks until a peer message arrives or a timeout expires, then returns it, so agents can listen for messages that aren't pushed to them.
Block until a peer message arrives (or the timeout passes), then return it. Use this to listen when messages are not pushed to you (e.g. in Codex).
| Name | Required | Description | Default |
|---|---|---|---|
| timeout_seconds | No | Max wait in seconds, default 300, max 1500 |
Changes observed during successful MCP inspections.
v0.1.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the full behavioral burden. It usefully discloses the blocking/waiting nature and that the call returns once the timeout passes, but it does not say what is returned on timeout (empty result vs error), whether the call is safe to run concurrently with send_message, or whether it consumes/drains a message.
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?
Two tight sentences with the core behavior front-loaded and the usage cue second. Nothing is redundant or padded.
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 one-parameter, no-output-schema listener, the description covers what the tool does and when to use it. The main gap is the timeout-expiry outcome, which an agent calling this tool will want to know before relying on a return value.
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 coverage is 100% and the single parameter already documents default 300 and max 1500. The description adds only the vague "or the timeout passes" and no syntax or semantics beyond the schema, so baseline 3 applies.
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 (block/wait) and resource (a peer message) plus the exit condition (timeout). The blocking semantics clearly differentiate it from a non-blocking read_inbox, but the description never names the sibling, so the differentiation is inferred rather than stated.
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?
"Use this to listen when messages are not pushed to you (e.g. in Codex)" gives an explicit when-to-use condition and a concrete scenario. It stops short of naming read_inbox as the alternative for messages that are already waiting, so the routing guidance is one-sided.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.