mark_as_unread

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the action and gives no information about side effects, whether the operation is reversible, whether it requires special permissions, idempotency, or what happens if the email is already unread.

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, clear, front-loaded sentence with no filler. It is concise but slightly under-specified for behavioral transparency, so it does not earn a top score.

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 with no output schema, the description and schema combine to convey the core operation and the important mailbox caveat. However, because there are no annotations, missing behavioral details such as success confirmation, errors, and effects on mailbox state leave a moderate gap.

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 description coverage is 100%, including useful details like the mailbox default and the importance of mailbox for UIDs from get_emails_by_label. The description itself adds no parameter semantics, but the schema already documents both parameters well.

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 'Mark an email as unread' uses a specific verb and resource, and clearly identifies the state change being performed. It naturally distinguishes itself from the sibling mark_as_read by naming the opposite state.

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?

Usage is implied by the action itself: use this tool when an email should be marked unread. However, there is no explicit guidance about when not to use it, prerequisites, or how it differs from related actions like mark_as_read or star_email.

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