createSession

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

Beyond the annotations, the description reveals important behavioral traits: no audio starts on creation, the returned ws_url is single-use and expires, and the API key must remain server-side. It also explains why the ws_url is safe to hand out. These details materially help an agent reason about side effects and security without guessing.

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 front-loaded with the core purpose and then provides concise, high-value usage and security context. The 'Tags: Sessions' line and the pointer to client-connection documentation are minor noise, but every other sentence earns its place. It is appropriately sized for the complexity of the tool.

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?

Although there is no output schema, the description identifies the essential return value (ws_url) and gives enough security and usage context for an agent to invoke the endpoint correctly. It does not cover error responses or any potential additional response fields, which would make it fully complete. Overall, the missing pieces are not critical for tool selection or invocation.

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 documents every parameter with 100% coverage, including clear descriptions for agent_id, type, metadata, and custom_variables. The tool description does not add parameter-level meaning, so the baseline of 3 applies. There is no gap for the description to compensate for.

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 opens with the exact action ('Create a voice Session') and precisely defines the resource: a short-lived, single-conversation reservation that returns a ws_url. It explicitly states that creating the session does not start audio on its own, which distinguishes it from call-dispatch and other voice-related tools. The 'step 1 of 2' framing further clarifies its role in the flow.

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 operational guidance: call this endpoint from your server with your API key, return only the ws_url to your client, and never let the API key reach the browser. It frames the endpoint as step 1 of 2, which tells the agent when it fits in the broader conversation flow. It does not explicitly name sibling alternatives or exclusion cases, but the usage context is strong.

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