line_send_message

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

With no annotations, the description must carry behavioral disclosure. It does a good job by explicitly stating the asynchronous nature ('Queue') and the return type ('an operation that can be polled'). This tells the agent that the action is not immediate and provides a follow-up mechanism. It does not disclose side effects, permissions, or failure modes, but the core behavior is covered.

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?

Two short sentences, each earning their place. The first states the primary action, and the second provides the crucial return/polling behavior. No redundant wording and the most important information is front-loaded.

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 description covers the essential send-and-poll workflow but is incomplete overall. It does not explain optional parameters, potential side effects, or what should be provided for 'reply_to' and 'idempotency_key.' Given there is no output schema and no annotations, more guidance would be needed for fully confident 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?

Schema description coverage is 0%, so the description must compensate. It does not explicitly explain any parameters. It implies 'text' and 'chat_id' by the phrase 'text message to a LINE chat,' but 'reply_to' and 'idempotency_key' are left entirely unexplained. The parameter names are somewhat self-explanatory, but the description adds little semantic value.

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 and resource: 'Queue a text message to a LINE chat.' This precisely identifies the tool's action and target, and because all siblings are retrieval/status tools, it is unambiguously distinguished as the send operation.

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 when to use this tool: when a text message needs to be sent to a LINE chat. However, it does not explicitly state when not to use it or mention any alternatives, though the sibling tools are all read-related and clearly not send alternatives. This is sufficient but not robust.

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