mark_unread

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

Annotations already indicate idempotent and non-destructive behavior. The description adds value by explicitly stating the side effect 'adds UNREAD' and noting reversibility, which aligns with and supplements the annotations.

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: one sentence plus a bullet for side effects. Every word is necessary, and the structure immediately conveys the core action and notable consequences.

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 (1 parameter, no enums, output schema present), the description covers the essential behavior. It could benefit from explaining what 'threadId' represents, but the context from sibling tools and the name likely suffices for an AI agent.

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 one parameter 'threadId' with no description, and schema description coverage is 0%. The description does not explain the parameter meaning, format, or constraints. While the name is self-explanatory, the description should add more context to compensate for the schema gap.

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 action: 'Mark a thread as unread.' The verb 'Mark' and resource 'thread' are specific. It distinguishes from sibling 'mark_read' implicitly through the opposite action, and the name itself clarifies the purpose.

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 mentions reversibility via 'mark_read,' which hints at when not to use it (if you want to undo). However, it does not provide explicit context on when to use this tool over alternatives like 'archive' or 'trash,' leaving some ambiguity.

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