Fetch lead lists and their contact counts to choose the right audience for Ballast cold email campaigns.
Lead lists with counts
This tool declares no required parameters. Add optional parameters from the input schema as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {},
"name": "list_lead_lists"
}
}| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
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 full behavioral burden. 'With counts' hints that counts are included in the response, but nothing is said about whether this is a read-only listing, whether results are paginated, whether it requires authentication/account scope, or how the counts are scoped.
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?
It is a single four-word fragment with zero waste, but that is under-specification rather than true conciseness. A full sentence could have added the verb and scope at minimal cost.
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 zero-parameter listing tool with no output schema, the description only needs to convey what is returned, and 'with counts' gestures at that. Still, it does not say whether all lead lists are returned or what a 'lead list' contains, leaving the agent to infer the payload shape without an output schema to fall back on.
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 tool takes zero parameters and schema coverage is 100%, so there is nothing for the description to document and no parameter ambiguity to resolve. Baseline 4 applies for a parameterless tool.
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 fragment 'Lead lists with counts' identifies the resource (lead lists) and hints at the return content (counts), which distinguishes it somewhat from siblings like list_leads or list_campaigns. However, it is a bare noun phrase with no verb and no explicit statement that it lists lead lists, so the purpose is only implied.
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?
There is no guidance about when to use this tool, when not to, or which sibling to prefer (e.g., list_leads vs list_lead_lists, or list_campaigns). The agent must infer usage entirely from the name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.