mark_read

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

Annotations already indicate this is a mutation (readOnlyHint=false), so the description does not need to restate that. It adds value by explaining the clear_mentions parameter and that max_id=0 means 'all', but it does not disclose side effects such as changes to unread counters or permission 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 extremely concise: a one-line purpose statement followed by a compact parameter list. Every word contributes information, with no filler or repetition.

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?

For a simple state-change tool, the description covers the core purpose and parameter semantics. An output schema exists, so return value details are not needed. The main gap is the lack of usage guidance, but that is covered under a separate dimension; within itself, the description is sufficiently complete.

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 has no field descriptions (0% coverage), so the description carries the burden. It explains max_id ('up to which id, 0 = all') and clear_mentions ('also reset @mentions'), which goes beyond the schema's default values. The chat parameter is left unexplained, but its meaning is fairly inferable from the tool name.

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 'Mark chat messages as read' (Пометить сообщения чата прочитанными), identifying a specific action and resource. It distinguishes itself from the sibling tool mark_stories_read by focusing on chat messages, and the optional clear_mentions behavior adds specificity.

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 provides no guidance on when to use this tool versus alternatives, no exclusions, and no context about prerequisites or side effects. It only lists parameters, leaving the agent to infer the usage context from the name alone.

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