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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and a closed-world scope, so the safety profile is covered. The description adds no behavioral context (rate limits, cost, freshness, how the 'gaps' are computed) and, because an output schema exists, its enumeration of returned categories is redundant rather than additive.

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 sprawling sentence built as a comma-separated list, with no front-loaded statement of what the tool does. The list content is dense but the structure buries any actionable lead.

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?

The tool is simple (one optional read-only parameter, output schema present), so completeness should be easy to achieve. Instead the description leaves the core purpose ambiguous and provides no routing guidance, which is a real gap for an agent deciding whether to call it.

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 parameter already documents the pattern and the 'leave out for newest report' default. The description only refers obliquely to 'a report's ranges/open calls' without adding format or fallback detail, so the baseline of 3 holds.

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 never states a verb or the action the tool performs; it only enumerates content categories ('creators to test again, free trials still running...'). The name 'campaign_health' and the title 'What would sharpen the answer' point in different directions, so an agent cannot confidently say what this returns or why. It reads closer to a restatement of internal output fields than a purpose statement.

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 indication of when to call this versus siblings such as refresh_report, get_latest_report, or list_campaigns. No prerequisites, no exclusions, no trigger conditions are given, leaving the agent to guess at the tool's role in the workflow.

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