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

Annotations already declare readOnly/idempotent/closed-world, so the safety profile is covered. The description adds real value beyond them: newest-first ordering, the breadth of notification categories, and an explicit prompt-injection warning that some texts quote public comments as UNTRUSTED content. It does not disclose truncation or pagination behavior when limit is hit.

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 but purposeful sentences: the resource and its contents up front, the ordering, then the untrusted-text caveat. No filler, though the category list is long enough to slightly blunt the front-loading.

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 describe the subject matter of returned items (which is its job), and the annotations cover safety. But for a list tool with a capped `limit` and an `unread_only` filter, the absence of any parameter or result-size behavior leaves the definition adequate rather than complete.

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?

Two parameters exist with 0% schema description coverage, and the description mentions neither `limit` nor `unread_only`. The agent gets no stated meaning for the cap (maximum 50) or for filtering to unread items, so it must guess from bare property names — a real gap the description was positioned to fill.

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 resource (the user's HypeFox notifications) and enumerates the concrete event types it surfaces (videos ready/failed, posts live/failed, pending approvals, Monday report, billing news). An agent can distinguish it from action tools like approve_video or retry_video, though it never names mark_notifications_read as the contrasting sibling.

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 'bell in the app' framing implies the read-the-inbox use case, but there is no explicit when-to-use or when-not-to-use guidance and no routing to alternatives such as list_pending_replies (which covers the OK-waiting items) or mark_notifications_read. The agent must infer the boundary itself.

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