line_reply_message

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

No annotations are provided, so the description carries full responsibility. It fails to disclose important behavioral traits such as reply token expiration, idempotency, error conditions, or the fact that replying consumes the token. The description is too minimal to inform an agent about side effects or requirements.

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 sentence, which is concise and front-loaded with the action. However, it sacrifices important details, making it insufficiently informative. It is not verbose, but the brevity reduces quality.

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 tool has 4 parameters (2 required), no output schema, and no annotations, the description is inadequate. It does not explain required parameters, how to format messages, response format, or error handling. A more complete description would include usage notes and parameter explanations.

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 coverage is 50% (messages and message have descriptions, channel_access_token and reply_token do not). The description adds marginal value by explaining reply_token as coming from a webhook event, but does not clarify channel_access_token or the relationship between messages and message. The schema already includes the note about messages being an array or using message, so the description offers no additional semantics.

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?

Description clearly states the action 'Reply to a LINE message' and identifies the key input 'reply token from a webhook event'. This differentiates it from siblings like line_send_message or line_broadcast by specifying the reply context. However, it does not explicitly contrast with siblings.

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 on when to use this tool versus alternatives. Does not mention that reply_token has an expiration time or that this should only be used for replying to webhook events. Lacks any context on prerequisites or limitations.

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