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

With no annotations, the description carries the full burden and does disclose the safety profile ('Read-only') plus a concrete truncation rule ('the last 100 activity events'), which prevents wrong assumptions about completeness. It does not mention auth/permission requirements or refresh/latency behavior, keeping it short of a 5.

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 dense sentence that front-loads the payload contents and ends with the read-only qualifier. Nothing is wasted, though the comma-separated field list is slightly hard 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?

There is no output schema, so the description must explain returns, and it does so by naming each data block and the 100-event cap. The main omission is sibling differentiation on a tool that clearly overlaps with several other campaign-getter tools.

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?

Only one parameter, and the schema already documents it fully ('Campaign id (UUID) from list_campaigns') at 100% coverage. The description adds no extra meaning about the id, so 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 names the resource (campaign monitor page) and enumerates exactly what is bundled: discovery config/stats, audience growth, last 100 activity events, event counts, and credits. It is specific, but it never distinguishes this composite view from nearby siblings like get_campaign_pulse, get_campaign_live_status, or get_campaign_activity.

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?

There is no guidance on when to call this versus the many overlapping siblings (get_campaign_analytics, get_campaign_discovery, get_balance, get_campaign_activity). The agent must infer that this is a one-shot dashboard read rather than aggregating several narrower tools.

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