latest_codeThe most recent verification code sent to a line, or nothing if none has arrived.
| Name | Required | Description | Default |
|---|---|---|---|
| from | No | Optional. Only consider messages whose sender contains this text, case-insensitively — a short code, say 32665. | |
| lineId | Yes | The line's id, from list_lines. | |
| service | No | Optional. Only consider messages Cleat attributed to this service (its id or name, e.g. facebook), or that carry this label from your workspace's contacts. |
Changes observed during successful MCP inspections.
Input schema / properties / fromAdded value: +{
+ "description": "Optional. Only consider messages whose sender contains this text, case-insensitively — a short code, say 32665.",
+ "type": "string"
+}Input schema / properties / serviceAdded value: +{
+ "description": "Optional. Only consider messages Cleat attributed to this service (its id or name, e.g. facebook), or that carry this label from your workspace's contacts.",
+ "type": "string"
+}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the burden, and it does state the primary behavior and the no-code result. However, it does not disclose whether reading the code consumes it, what permissions are needed, or how a verification code is identified among messages.
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, front-loaded sentence conveys the core operation and the important empty-result case without wasted words or redundant detail.
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 simple retrieval tool with a fully described schema and explicit return behavior, the description is mostly sufficient. The main missing context is sibling-aware usage guidance and a bit more behavioral transparency, but nothing critical is absent.
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?
The input schema already provides full descriptions for all three parameters, so the baseline is 3. The tool description adds no additional meaning about how lineId, from, or service affect the result beyond what the schema already states.
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?
The description clearly identifies the tool as returning the most recent verification code for a line, including the empty case. It is specific and understandable, though it does not explicitly contrast itself with sibling tools such as wait_for_code or list_messages.
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?
No explicit guidance is given about when to use this tool versus its siblings. The phrase 'or nothing if none has arrived' implies this is a non-blocking check, but it never tells the agent to prefer latest_code over wait_for_code or to use list_messages for raw message history.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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