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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context: it enumerates the four possible states and notes the address is shown masked, which is a privacy behavior worth knowing. Not a contradiction, and it exceeds minimal annotation repetition, so a 3 is fair.

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?

A single front-loaded sentence covering the question and its possible answers. No waste, though the phrasing is slightly conversational. Efficient and readable.

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 one-param read-only query tool, the description covers what the return states mean and mentions masking, which is helpful given no output schema. However, it doesn't reference the related notification-lifecycle siblings an agent might need, leaving a small gap in routing completeness.

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 coverage is 100% and the single api_token parameter is fully documented in the schema, including the header-alternative guidance. The description adds nothing about parameters. Baseline 3 is appropriate when the schema does all the work.

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 states a specific query about email notification status, enumerating the possible states (none, pending, active, unsubscribed). It doesn't explicitly contrast with siblings like confirm_notification_email, set_notification_email, or remove_notification_email, but the 'Whether...' framing clearly signals a read/check operation distinct from those write-oriented siblings.

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 explicit when-to-use guidance. It explains the possible return values but doesn't tell the agent when to call this vs the related notification tools (confirm_notification_email, set_notification_email). The purpose is implied but alternatives are not addressed.

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