mark_as_read

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It accurately describes the state-changing action ('marks messages as read') which is a write operation, but it does not disclose side effects such as read receipts, whether the action is idempotent, or any permission requirements. The core behavior is clear, but additional context is lacking.

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, well-structured sentence that conveys the essential action without unnecessary words. It is immediately scannable and contains no redundant information.

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 simplicity of the tool and the fully described schema, the description is mostly complete for a state-changing action. It defines what the tool does and the parameters are well-documented. However, since there is no output schema and the description does not mention return values or error conditions, it is not fully comprehensive, but sufficient for straightforward use.

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?

The input schema provides 100% coverage with meaningful descriptions for all three parameters (id, chat_type, message_id). The description itself adds no additional parameter semantics beyond the schema, so the baseline score of 3 applies.

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 'marks' and the resource 'messages in a channel or conversation', with the specific scope 'up to the given message ID'. This distinguishes it from sibling tools like send_message or get_messages, as there is no other tool for marking read state in the list.

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 its use case by defining the action, but it does not explicitly state when to use it versus alternatives, nor does it mention any exclusions or prerequisites. No guidance is given for when not to use it.

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