MCP Gemini Server

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

With no annotations provided, the description carries full burden but lacks critical behavioral details. It mentions statefulness and returns a sessionId, but doesn't disclose session lifecycle (timeouts, persistence), authentication requirements, rate limits, error conditions, or what happens if invalid parameters are provided. For a tool that creates persistent resources, this is a significant gap.

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 in two sentences that front-load the core purpose and key outputs, then mention optional parameters. Every phrase earns its place by conveying essential information about the tool's function and return value without redundancy or unnecessary elaboration.

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 complex tool with 5 parameters, nested objects, no annotations, and no output schema, the description is insufficient. It doesn't explain the sessionId format, how to use it with sibling tools, error handling, or the implications of stateful sessions. The lack of behavioral transparency and minimal parameter guidance leaves significant gaps for an agent to use this tool effectively.

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 fully documents all 5 parameters. The description adds minimal value beyond the schema by mentioning 'initial conversation history' and 'session-wide generation/safety configurations' in general terms, but doesn't provide additional semantic context about how these parameters interact or affect behavior.

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 specific action ('Initiates a new stateful chat session'), identifies the resource ('with a specified Gemini model'), and distinguishes from siblings by emphasizing the stateful nature and session creation, unlike other tools that handle content generation, file operations, or cache management.

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 implies usage context by mentioning 'subsequent chat messages' and 'session-wide' configurations, suggesting this is for starting multi-turn conversations. However, it doesn't explicitly state when to use this versus alternatives like gemini_generateContent for single-turn interactions or how it relates to gemini_sendMessage for continuing chats.

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