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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description adds relevant behavior beyond that: it returns macro-level aggregate counts across the entire workspace, compares against the prior period for trend analysis, and constrains results to 7, 30, or 90 days. It does not cover permissions, rate limits, or response structure, but it adds meaningful context for a read-only aggregate.

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?

The description is three sentences and front-loads the purpose, then return details, then routing guidance. There is minor redundancy between the first sentence and the title, and between 'aggregate totals' and 'macro-level aggregate counts,' but no wasted instruction and the structure is easy to scan.

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?

No output schema exists, so the description must describe the result, and it does: workspace-wide macro aggregates, the metric list, the time windows, and prior-period comparison. Combined with annotations that cover safety and a fully documented single parameter, an agent has enough information to call the tool correctly.

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%, and the single 'days' parameter is already documented with its allowed values. The description reinforces the 7/30/90-day window but adds no new semantics such as default behavior, format, or filtering effects. This is the expected baseline when the schema carries the parameter documentation.

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-resource: returns workspace-wide aggregate email outreach totals and trends. It lists the exact aggregate counts (total sends, replies, positive replies, bounces, won deals) and the 7/30/90-day windows, and names the two sibling alternatives it should not replace. This clearly distinguishes it from get_campaign_stats and get_campaign_analytics.

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 explicit when-to-use guidance: 'USE THIS for high-level workspace executive summaries.' It also gives explicit when-not-to-use guidance and names alternatives: 'DO NOT use for a single campaign (use get_campaign_stats instead) or for provider/mailbox breakdowns (use get_campaign_analytics instead).' No inference is required.

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