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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context beyond that — the period-over-period comparison, the presence of 'measurement caveats', and the 'honest headline' framing signal data-quality caveats accompany the numbers — but says nothing about data freshness, scope, or what an empty workspace returns.

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 compact sentence with the primary content (KPIs) front-loaded and no filler. The phrase 'the honest headline' is evocative but slightly opaque jargon that costs a little clarity.

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 must carry the return-content burden, and it does list the substantive payload (KPIs, comparison, caveats, proposal count). For a zero-required-parameter read tool this is adequately complete, missing only response shape or freshness details.

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%, with the single optional 'window' enum already documented as days with a data-following default. The description's 'vs the previous period' adds a little interpretive context for how window affects the comparison, but no format or default details beyond the schema. 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 enumerates the concrete contents returned: spend, paid installs, cost per install versus previous period, a headline, measurement caveats, and a count of pending proposals. That is specific enough to separate it from siblings like get_campaign or list_proposals, though the action verb is only implied by 'Home KPIs' rather than stated.

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 word 'Home' weakly implies this is a starting dashboard, but there is no explicit when-to-use guidance, no conditions, and no named alternative (e.g. the relationship to list_proposals for proposal detail is left implicit). An agent must infer the routing decision entirely.

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