vapi-mcp-server

vapi_end_call

End an active Vapi call by providing the call ID. This halts the call and releases resources.

Instructions

End an active Vapi call

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "id": "<id>"
    },
    "name": "vapi_end_call"
  }
}

Input Schema

Name	Required	Description	Default
`id`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.0Jun 21, 2026

TDQS

C2.8/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, description bears full burden for behavioral disclosure. It implies a destructive action (ending a call) but does not specify that the call must be active, what happens if already ended, or any side effects. Lacks permission or safety context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Single sentence is concise and front-loaded. However, it could benefit from slight elaboration (e.g., mentioning the parameter) without adding significant length.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple action tool with one parameter and no output schema, the description is minimally adequate. But it lacks details about input format, response, or error conditions, which would be helpful for an AI agent.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters2/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema has one required parameter 'id' with 0% description coverage. The tool description does not explain what 'id' refers to (e.g., call ID, session ID?), leaving ambiguity. Agent must infer from context.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states the action 'End' and the resource 'active Vapi call', providing a specific verb-resource pair. It implicitly distinguishes from sibling tools like vapi_create_call (create) and vapi_get_call (get), but doesn't elaborate on scope or context.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool versus alternatives like vapi_evaluate_call or vapi_create_call. No mention of prerequisites (e.g., call must be active) or consequences of invocation.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.