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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds useful scope information about what event categories are surfaced and implies a cursor-style incremental read, but says nothing about auth requirements, result limits, or whether items are unread-only. With annotations doing the heavy lifting, this is adequate but thin.

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 short sentences, front-loaded with the content scope and followed by the incremental-fetch mechanic. Nothing is padded, though the phrasing is terse enough that key behaviors (first call, limits) are omitted rather than compressed.

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?

An output schema exists, so return-value explanation is not required, and annotations cover safety. What is missing is anything about pagination limits, default time window, or auth handling for a 2-parameter tool at 0% schema description coverage — plus the misleading `next_since` name reduces confidence for an agent wiring up the call.

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 0%, so the description must carry parameter meaning — and it partly does by explaining that an ISO time value restricts results to new items. However, it references `next_since`, a name that does not exist in the schema (the actual parameter is `since`), which risks an agent passing an invalid argument. The api_key parameter is not addressed 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?

The description enumerates the concrete event types returned (replies to your threads, mentions, points, moderation outcomes, job decisions), which makes the resource unmistakable and distinguishable from siblings like list_threads or my_points. It lacks an explicit verb (it is implicitly a 'read/list personal notifications' operation), so it falls just short of a 5.

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?

It implies the incremental-polling workflow ('Pass back next_since to get only new items') but never states when to choose this over alternatives, whether a first call should omit the time filter, or how far back a null value reaches. Usage is inferable from context rather than stated.

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