client_markChatUnread

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

With no annotations available, the description must fully disclose behavioral traits. It merely restates the action without mentioning side effects, reversibility, permissions, or return behavior. It provides no additional transparency beyond the tool's name.

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 very short but under-specified. It restates the tool's name with little added context, and its brevity is not informative. It lacks structure but does not waste words, placing it below a fully acceptable standard.

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 mutation tool with no annotations and no output schema, the description is severely incomplete. It does not explain the operation's scope, effects, or any special considerations, leaving the agent without sufficient context to invoke the tool confidently.

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 for both parameters (chatId and sessionId), so the description does not need to add parameter details. The schema descriptions are clear, satisfying the baseline of 3.

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 ('mark') and resource ('chat'), clearly stating the operation as marking a chat unread. However, it does not differentiate from the sibling tool 'chat_markUnread', which likely serves a similar purpose in a different context.

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 guidance is provided on when to use this tool versus alternatives such as 'chat_markUnread'. The description offers no context, prerequisites, or exclusions, leaving the agent to infer usage.

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