mark_email

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It implies a mutation (marking an email) but does not mention side effects, permanence, permission requirements, or error behavior. The description adds no context beyond what the schema already encodes.

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, front-loaded sentence that immediately conveys the action and the accepted flags. It is concise with no wasted words, making it easy to parse and understand.

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?

The tool is relatively simple with a fully descriptive schema, but the description lacks any contextual detail about side effects, return behavior, or usage scenarios. For a mutation tool without annotations, this is a clear gap, though the schema covers parameter meaning, leaving the overall description minimally viable.

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%, so the baseline is 3. The description does not add extra meaning beyond the schema; it merely restates the flag values that are already defined in the enum. No additional parameter semantics are provided.

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 tool's function: marking an email with a specific flag, listing the exact flag values (read/unread/flagged/unflagged). This uses a specific verb ('mark') and resource ('email'), distinguishing it from siblings like fetch_emails or move_message.

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 such as move_message or copy_message. It does not specify prerequisites, typical use cases, or exclusions. The sibling list suggests context, but the description itself lacks any usage direction.

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