Retrieve Unibox emails with optional filters by campaign, lead email, sending account, or unread status. Review sent, replied, and manual messages.
List Unibox emails (sends, replies, manual). Filter by campaign, lead email, sending account, or unread. # NOTE: this endpoint is rate-limited to 20 req/min by Instantly.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| eaccount | No | ||
| lead_email | No | ||
| campaign_id | No | ||
| unread_only | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the behavioral disclosure burden. It explicitly discloses a rate limit (20 req/min by Instantly) and clarifies the scope of emails returned. It does not describe response shape or pagination behavior, but the rate-limit note is valuable and the list operation is inherently non-mutating.
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?
The description is two focused sentences with no filler. The core purpose and filters are front-loaded, and the rate-limit note is appended cleanly as a useful operational warning.
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?
The description covers the essential list-and-filter behavior and the rate limit, and all parameters are optional so a minimal call is easy to construct. However, it omits the 'limit' parameter behavior and provides no output/return shape, which an agent would have to infer given there is no output schema.
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%, and the description compensates by mapping filters to meaningful concepts: campaign, lead email, sending account, and unread. This is especially helpful for the cryptic eaccount parameter. However, the 'limit' parameter is not mentioned at all, leaving one parameter without semantic guidance.
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 uses a specific verb ('List') and resource ('Unibox emails'), and adds scoping details ('sends, replies, manual') plus the main filter dimensions. This makes it clearly distinct from sibling tools like get_email, count_unread, and list_leads.
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 description gives clear context for when to use the tool: to list Unibox emails with optional filters. However, it does not explicitly state when not to use it or point to alternatives such as get_email for a single email or count_unread for counts.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.