Link Rich Menu to User

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

With no annotations provided, the description carries the full burden of behavioral disclosure. 'Link' implies a mutation, but the description does not mention whether linking overrides an existing rich menu, whether the user must already exist, or any permission requirements. This is a significant gap for a mutation tool.

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 a single, concise sentence that immediately conveys the action and target. It is efficiently front-loaded with no unnecessary words or repetition. The brevity is appropriate for a straightforward operation.

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 lack of annotations and output schema, the description is too minimal to fully prepare an agent. It does not explain whether linking is idempotent, whether it replaces an existing link, or any failure conditions. For a mutation tool with no safety annotations, more context is needed to ensure correct 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 provides 100% coverage with descriptions for both userId ('LINE User ID') and richMenuId ('Rich menu ID'). The description adds no additional semantic meaning beyond what the schema already states, so the baseline of 3 is appropriate.

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 the verb 'Link' and the resource 'rich menu to a specific user', which clearly conveys the operation. It implicitly distinguishes from siblings like unlink_rich_menu_from_user and set_default_rich_menu by specifying 'a specific user', but does not explicitly call out those alternatives. The purpose is unambiguous and easily differentiated.

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?

No guidance is provided on when to use this tool versus related tools such as set_default_rich_menu or unlink_rich_menu_from_user. The description simply states what it does without mentioning context, prerequisites, or exclusions. An agent would have to infer usage from the name and parameters.

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