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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world, so the safety profile is covered. The description adds that the result is aggregated totals and rates rather than raw records, which is mild added value, but says nothing about retention clipping, timezone handling, or response shape beyond that.

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 with no filler; the scope and return content come first. It is arguably too terse for a tool with non-obvious date semantics, but nothing is wasted.

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 three optional parameters and no output schema, the description partly compensates by naming the return content ('totals and rates'). However, it omits any note about the default 7-day window or plan retention clipping, which are behavioral facts an agent should know before calling.

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 description coverage is 100%; the schema fully documents startDate/endDate defaults and the excludeOOO flag. The description contributes no parameter semantics of its own, so the baseline 3 applies.

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 verb (roll-up) and resource (all campaigns, workspace-wide), with scope ('across the workspace') that implicitly separates it from the per-campaign sibling get_campaign_analytics. It never names that sibling explicitly, so differentiation is left partly to inference.

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?

Usage is only implied: the workspace-wide framing suggests this tool when you want an aggregate rather than a single campaign's numbers. There is no explicit 'use this instead of get_campaign_analytics when...' guidance or mention of prerequisites.

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