mark_read

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

Discloses that this is a 'real action the other party can see' (side-effect/destructive behavior) and honestly fails if nothing to mark. No annotations are provided, so the description fully covers behavioral traits.

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 sentences, no wasted words. Front-loaded with the core action and user guidance. Every sentence adds value.

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 no annotations, no output schema, and 2 parameters, the description covers all needed aspects: purpose, usage guidelines, behavioral transparency, and parameter semantics. Complete for its complexity.

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 100% with descriptions. The description adds context beyond the schema: chatId as returned by list_conversations, and messageId semantics with omission default. Baseline 3, improved by additional context.

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 tool sends a LINE read receipt and marks a conversation read up to a messageId or the latest. Verb and resource are specific, and it distinguishes from siblings like send_message or get_chat_messages.

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?

Explicitly states 'Use ONLY when the user explicitly wants to mark a chat read' and contrasts with reading tools (get_chat_messages, get_unread_digest) that never mark read, providing clear when-to-use and when-not-to-use guidance.

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