Push Text Message

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

Annotations provide destructiveHint=true, so description carries lower burden. Description adds minimal extra context beyond that it pushes a message. Does not mention potential side effects (e.g., LINE API restrictions, user must be a friend) or rate limits.

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 concise sentences, first sentence dedicated to purpose, second to usage. No wasted words.

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?

Tool has simple parameters and no output schema. Description adequately covers purpose and basic usage but lacks error conditions, prerequisites (e.g., user must be a LINE friend), or integration details. Sufficient for a simple 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?

Schema coverage is 50% (only message parameter has description). Description mentions 'simple text message' and 'plain text', which relates to message but does not explain the nested structure or userId parameter beyond what schema provides. Lacks compensation for missing schema descriptions.

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 verb 'Push' and resource 'text message to a user via LINE', distinguishing it from sibling tools like broadcast (sends to all) and flex (formatted message) by specifying 'plain text without formatting'.

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 second sentence explicitly states when to use this tool ('for sending plain text messages without formatting'), implying it is not for formatted messages. However, it does not explicitly state when not to use it (e.g., for broadcasting) or provide alternatives.

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