Show Loading Indicator

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

With no annotations, the description carries the full burden for transparency. It only states that a loading animation is displayed, but does not disclose potential side effects (e.g., timing, whether it blocks further actions, or if it auto-dismisses). This lack of behavioral detail is a 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 a single, front-loaded sentence that immediately conveys the action and context. It is concise and contains no redundant information.

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 simplicity of the tool and the absence of an output schema, the description covers the basic purpose. However, it omits practical context such as the expected duration of the loading indicator, any prerequisites (e.g., chat must exist), or limitations. This is acceptable for a minimal tool but leaves some gaps.

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 schema already includes a clear description for chatId (including the fallback to DEFAULT_UID), and schema coverage is 100%. The tool description adds no additional meaning to the parameter, matching the baseline of 3.

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 tool's function: 'Display a loading animation in the LINE chat to indicate processing.' It uses a specific verb and resource, and it is easily distinguished from sibling tools that focus on sending messages (push, broadcast, multicast) or managing rich menus.

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 does not explicitly state when to use this tool versus alternatives, such as indicating it should be used before a push or as a temporary UI state. While the tool's purpose is distinct, comparative usage context is missing.

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