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

Annotations already declare readOnlyHint, so the safe-read profile is covered; the description adds real value beyond that with ordering (newest first), scope (owner-scoped, all sent mail), the exact event types surfaced, and cursor-based pagination behavior. It does not mention volume/rate considerations that matter for a polling tool, but the essential traits are disclosed.

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 dense sentences, front-loaded with what the feed is before the polling instruction; every clause carries information. The parenthetical list of event types is slightly cluttered but earns its place by defining the feed's contents.

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?

With no output schema, the description does the necessary work by naming the payload fields (subject, recipient, cursor) and the ordering. Enough to call the tool correctly; only minor gaps remain around error handling and event-shape details.

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 both parameters are documented there, including the cursor-as-`since` polling trick. The description restates the same cursor convention without adding syntax, defaults, or edge-case behavior (e.g. what happens with an invalid or future timestamp), so it matches the baseline rather than exceeding it.

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+resource: a recent engagement feed of opens, clicks, forwards and print/copy signals across ALL sent mail, newest first, with subject and recipient per event. An agent can immediately tell this is the notification/engagement stream rather than aggregate reporting (mAYL_stats/metrics) or raw audit events.

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?

Gives explicit polling instructions — pass the returned `cursor` back as `since` to get only new activity — which is the primary usage pattern, and notes the owner scope. It never names a sibling tool or states when another tool would be the better choice.

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