Create Vapi Assistant

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

With no annotations provided, the description carries full burden but offers minimal behavioral insight. It mentions configurable attributes but doesn't disclose whether this is a mutating operation (implied by 'Create'), what permissions are needed, whether there are rate limits, what happens on success/failure, or what the return value contains. This leaves significant gaps for a creation tool.

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 efficiently structured as a single sentence that front-loads the core purpose and enumerates key parameters. While it could be slightly more polished, every word serves a purpose and there's no redundancy.

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 creation tool with 9 parameters, no annotations, and no output schema, the description is insufficient. It doesn't explain what happens after creation (e.g., returns an assistant ID), what errors might occur, authentication requirements, or how this tool relates to the broader Vapi workflow. The agent would need to guess about important behavioral aspects.

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 100%, so the schema already documents all 9 parameters thoroughly. The description adds marginal value by listing some key parameters (name, first message, system prompt, LLM model, voice) but doesn't provide additional context beyond what's in the schema descriptions. This meets the baseline for high schema coverage.

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 states the action ('Create') and resource ('Vapi voice assistant'), and lists key configurable attributes. It distinguishes from siblings like vapi_update_assistant or vapi_get_assistant by focusing on creation, but doesn't explicitly contrast with vapi_create_squad which creates a different resource type.

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 guidance on when to use this tool versus alternatives like vapi_update_assistant for modifications or vapi_create_squad for creating a different entity. The description simply states what the tool does without providing context about prerequisites, timing, or decision criteria.

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