Create Rich Menu

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

Annotations already declare destructiveHint=true, so the description is consistent with that. It adds context about image generation and default registration, but it does not disclose side effects such as replacing an existing default rich menu or any limits. Given the annotation covers the mutating nature, the description adds some value but could be richer.

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 short (two sentences) and front-loaded with the main purpose. There is minor redundancy ('based on the given actions' and 'based on the given action') but it is not verbose. It earns a 4 for being efficient and readable.

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?

The tool is moderately complex (multiple action types) but the schema provides detailed structure. However, the description omits any return value or error behavior, and does not explain what happens to the previous default when this one is set. Given no output schema, the description should at least hint at the result. It is adequate but incomplete.

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% (both parameters have descriptions), so the description does not need to add parameter details. The tool description mentions 'actions' and 'image' but does not add meaning beyond the schema. Baseline 3 is appropriate since the schema carries the parameter documentation.

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 states a clear verb ('Create') and resource ('rich menu'), and adds that it generates/upload an image and registers it as default. This distinguishes it from siblings like delete_rich_menu, though it does not explicitly contrast with set_rich_menu_default. It is specific enough for an agent to know what the tool accomplishes.

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 no guidance on when to use this tool versus alternatives like set_rich_menu_default or delete_rich_menu. It does not mention conditions or exclusions, leaving the agent to infer from the 'registered as default' phrase. This is a significant gap for a mutating tool.

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