NanoBanana MCP

set_aspect_ratio

Configure the aspect ratio for image generation and editing sessions to ensure consistent dimensions across creations. Specify ratios like 16:9 or 1:1 before processing images.

Instructions

Set the aspect ratio for subsequent image generation and editing in this session. Must be called before generating/editing images if a specific ratio is desired.

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": {
      "aspect_ratio": "<aspect_ratio>"
    },
    "name": "set_aspect_ratio"
  }
}

Input Schema

Name	Required	Description	Default
`aspect_ratio`	Yes	The aspect ratio to use for image generation/editing
`conversation_id`	No	Session ID to apply this setting to (default: 'default')

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.1.1Mar 16, 2026

TDQS

A4/5.0

Behavior3/5

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

With no annotations, the description carries the full burden. It discloses the session-scoped effect and the ordering requirement, but does not clarify behavior like overriding previous settings, persistence across sessions, or the relationship between 'session' and the conversation_id parameter.

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

Conciseness5/5

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

The description is two concise sentences, front-loaded with the verb and key resource, followed immediately by the usage rule. No wasted words.

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

Completeness4/5

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

For a simple setter tool with a fully described schema, the description covers core purpose and usage timing. Minor ambiguity exists around 'session' vs conversation_id and default ratio behavior, but overall it is sufficiently complete for the tool's simplicity.

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

Parameters3/5

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

Schema description coverage is 100%: both parameters have descriptions, and aspect_ratio has a detailed enum. The description adds no additional parameter semantics, so baseline 3 is appropriate.

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

Purpose5/5

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

The description clearly states the tool's function: 'Set the aspect ratio for subsequent image generation and editing in this session.' It uses a specific verb and resource, and distinguishes itself from sibling tools like set_model and the actual image generation/editing tools.

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

Usage Guidelines4/5

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

Explicit guidance is given: 'Must be called before generating/editing images if a specific ratio is desired.' This states when to use the tool and the condition under which it applies, though it does not mention alternatives or explicit exclusions.

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

Deploy Server