mark_read

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

With no annotations, the description carries the full burden, and it does disclose the per-topic unread cursor side effect and the fact that topic_id is needed for forum supergroups. However, it does not mention permissions, idempotency, or whether the operation only affects the current user's read state.

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 with no filler: the main action is front-loaded, and the conditional forum behavior is placed after it. Every clause earns its place.

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 two-parameter mutation, the description covers the core action and the one special-case parameter, but no annotations or output schema exist and there is no mention of the return value or how this relates to read_messages. It is minimally adequate but leaves selection and result expectations unstated.

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 only 50% since chat_id lacks a description; the description does not add meaning to chat_id. It does reinforce topic_id's purpose ('1 for the General topic', 'per-topic unread cursor'), but much of that duplicates the schema's topic_id description.

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 opens with a specific action and resource ('Mark a chat as read') and adds a clear special-case behavior for forum supergroups. It does not explicitly contrast itself with the sibling read_messages, but the chat-level wording helps distinguish it from message-level 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?

No explicit when-to-use guidance or alternative tool is mentioned; the only conditional is about topic_id, which is parameter-level guidance. Given the presence of the sibling read_messages, an agent receives no help choosing between the two.

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