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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context by revealing that this tool reads directly from nev-api, is the operational source of truth, and that the alternative report lags behind due to the analytics pipeline. It also discloses the kind of counters and rates an agent can expect.

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 well-structured and front-loaded with the core purpose and metric list. Each sentence earns its place: metric enumeration, source-of-truth positioning, alternative routing, and follow-up guidance. There is no filler.

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?

For a single-parameter, read-only tool, the description is remarkably complete. It lists all returned metrics (compensating for the missing output schema), explains data freshness and credibility relative to a sibling, provides usage and alternative conditions, and suggests a follow-up tool. An agent has everything needed to invoke this tool correctly and interpret results.

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% for the single campaign_id parameter, and the schema description already explains where to get it (nevent_list_campaigns or nevent_create_campaign). The description repeats the nevent_list_campaigns source but adds no new parameter meaning beyond the schema.

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 ('Get') and resource ('delivery and engagement counters nev-api holds for one campaign'), and enumerates the exact metrics returned. It clearly differentiates itself from the sibling nevent_campaign_report by positioning itself as the operational source of truth.

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?

The description gives explicit when-to-use guidance: use it right after a send and prefer it over nevent_campaign_report when the two disagree. It also specifies when to use the alternative (comparing many campaigns, slicing by dimension, joining with analytics) and tells the agent how to obtain campaign_id from nevent_list_campaigns.

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