Read messages from a LINE chat, using a before cursor to fetch older history when needed.
Read messages from a LINE chat. Use before as a cursor for older history.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | ||
| before | No | ||
| chat_id | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must carry the behavioral burden. 'Read' clearly signals a non-mutating operation, and the cursor note reveals pagination behavior. Still, it does not disclose rate limits, authentication needs, default ordering, or whether messages are marked as read.
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 with no filler. The core purpose is front-loaded, and the pagination hint earns its place without verbosity.
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 purpose and one parameter's behavior, which is enough for basic invocation. However, with no output schema and no annotations, it leaves the return shape, message ordering, and default limit behavior unspecified.
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 for all parameters. It only explains 'before' as a cursor for older history; 'chat_id' and 'limit' receive no semantic explanation beyond their names and schema constraints.
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 uses a specific verb and resource: 'Read messages from a LINE chat.' This clearly distinguishes the tool from siblings like line_send_message, line_get_status, and line_search_chats, which perform different operations.
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 gives one concrete usage hint: 'Use before as a cursor for older history,' which helps agents paginate. However, it does not explicitly state when to prefer this tool over alternatives or mention any exclusions, so tool-selection guidance is mostly implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.