gemini_start_chat

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

Annotations set readOnlyHint false, destructiveHint false, etc. Description adds that session maintains history and returns session_id. Discloses behavioral trait of context preservation. No contradictions.

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?

Very concise – three sentences plus structured Args/Returns sections. Front-loaded with main purpose. No redundant words. Each sentence adds value.

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?

Given the tool's simplicity (1 optional param, returns session_id), the description fully covers usage: what it does, how to use the output, and the model parameter. Sufficient for an AI agent.

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?

Single parameter 'model' has 0% schema description coverage. Description provides default value (gemini-3.0-flash) and explanation, adding meaning beyond the schema. Could list available models, but adequate for a default parameter.

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?

Clearly states 'Start a new multi-turn chat session with Gemini' with specific verb and resource. Distinguishes itself from siblings like gemini_chat and gemini_reset by indicating it initiates a session that maintains history.

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?

Explains that the session maintains conversation history for context, and instructs to pass the returned session_id to gemini_chat. Implicitly guides when to use this tool. Could explicitly state when not to use, but sufficient for typical use.

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