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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), and the description adds substantive behavior beyond them: a 35-day retention window, the 7-day default range, oldest-first ordering, and the cursor/has_more pagination contract. This is meaningful operational context the agent cannot get from the annotations.

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?

Purpose and use case are front-loaded, and the pagination workflow is clearly sequenced. The inline dump of the full return shape is dense, but since there is no output schema it largely earns its place, leaving only mild redundancy.

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 carries the return contract (change object fields, next_cursor, has_more) and adds retention limits, ordering, and a citation requirement. Nothing an agent needs to invoke and use the result correctly appears to be missing.

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%, so the schema already documents alert, limit, since, and cursor. The description reinforces the cursor workflow and gives an example, but adds little syntax or format detail beyond the schema. Baseline 3 is appropriate.

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 names a specific verb+resource ('what changed in the series') and scopes it precisely to 'the series the user has alerts on' with ordering ('oldest first'). This scope cleanly separates it from siblings like get_revisions or get_series, which are not alert-scoped.

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 gives an explicit use case ('answer what changed since my last check without webhooks') and a concrete first-call protocol (no arguments = last 7 days, or pass 'since'). It does not name alternative tools (e.g. get_revisions) or state when to prefer them, so it stops short of a 5.

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