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

The annotations already declare this as a safe read operation, so the description's real contribution is the auth tier requirement, the email-only scope, the disclosure that segment_breakdown returns empty for single-segment campaigns, and the 0.1% complaint-rate risk threshold with a pointer to nevent_get_campaign_deliverability. These are genuine behavioral traits beyond structured fields; only failure behavior (invalid campaign_id) is unaddressed.

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?

It is front-loaded with the resource scope and view enumeration, and nearly every sentence earns its place (triggers, thresholds, exclusions, auth). The one inefficiency is that the per-view breakdown duplicates the schema's view description field word for word, which is redundant token cost.

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 still conveys what each view returns, the constraints on use, the escalation thresholds, and the correct alternative tool. Nothing an agent needs in order to call this correctly on a 2-parameter read tool is 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 description coverage is 100% and both parameters are fully documented in the schema, so the baseline is 3. The description restates the view enum almost verbatim from the schema rather than adding meaning, and says nothing about campaign_id beyond what the schema already states.

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 resource with explicit scope ('Unsubscribes and spam complaints of ONE campaign') and enumerates the three views and what each returns. It names the sibling it is not ('For tenant-wide totals use nevent_get_suppressions_summary'), so an agent can distinguish it from nevent_get_campaign_metrics and nevent_get_suppressions_summary without opening a schema.

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 concrete triggers ('explain a spike in nevent_get_campaign_metrics.unsubscribes', 'compare how audiences reacted'), an explicit exclusion ('For tenant-wide totals use nevent_get_suppressions_summary'), a hard applicability constraint ('Email campaigns only'), and an access prerequisite ('Requires ADMIN, OWNER or SUPERADMIN'). No inference is left to the agent.

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