set_email_read_state

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

Annotations already declare this as non-read-only, idempotent, and non-destructive, providing the core safety profile. The description adds 'Explicitly' and 'one selected', reinforcing the mutating and scoped nature, but does not disclose additional behavior such as persistence or side effects beyond what annotations imply.

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, focused sentence with no filler. It states the action, the resource, and the possible outcomes in a clear, front-loaded manner.

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 simple and the description covers its core purpose. An output schema exists, so return values need not be described. Annotations handle safety aspects. The description could be slightly more explicit about parameter roles, but overall it is sufficient for a low-complexity tool.

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. It clarifies that 'emailId' selects the email and 'isRead' sets the state, but 'storeId' is left unexplained. The description partially maps to two of three parameters but leaves a key parameter ambiguous.

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') with a clear resource ('Outlook Web email') and a precise outcome ('read or unread'). It also specifies scope ('one selected'), effectively distinguishing it from siblings like get_email (which reads) and create_reply_draft (which composes).

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 implies the tool is for changing the read state of an email, which is a distinct operation from the siblings. However, it does not explicitly state when to use this tool versus alternatives, nor does it mention any exclusions or prerequisites.

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