markAsUnread

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

No annotations are provided, so the description carries the full behavioral burden. It discloses that the change is pushed to the email server (a remote mutation rather than a local flag), which is useful, but says nothing about idempotency, required permissions, or what happens on an invalid UID.

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 tight sentences with the core action front-loaded and no filler. Nothing is redundant, though there is very little content for the length to be praised further.

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 flag toggle with no output schema, the description covers the essential action. It falls short on the folder scoping parameter and on failure behavior, which an agent would want before invoking a server-side mutation.

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 0%, so the description must compensate, and it does not. It references the UID only as an identifier ('using its UID') with no format or validity notes, and the 'folder' parameter (default INBOX) is never mentioned at all.

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?

States a specific verb and resource ('Mark a specific email as unread'), and the phrase 'a specific email' implicitly separates it from the sibling markMultipleAsUnread. It stops short of naming that sibling, so the differentiation is inferable rather than explicit.

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 when-to-use guidance, no prerequisites, and no mention of the obvious alternatives (markAsRead, markMultipleAsUnread). The agent must infer from the name alone when this is the right tool.

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