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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), yet the description adds substantive behavioral rules: email totals are omitted when the campaign has no email steps, and the leading A/B variant is only reported once each variant has 50+ sends. These are non-obvious output behaviors not captured by annotations.

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 a single dense but well-structured sentence with the subject ('A campaign's results') front-loaded, followed by progressively finer detail. Every clause carries information, though the length is at the upper edge of comfortable scanning.

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 carries the full burden of explaining return values, and it does so thoroughly across email, LinkedIn, lead-outcome, per-step and per-variant dimensions, including the conditional omission rules. Nothing needed to interpret the response 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%, so the baseline is 3, but the description adds real meaning beyond the schema: it explains that the optional start/end dates limit opens, clicks and replies only, and gives the YYYY-MM-DD format. That scoping semantic is not derivable from the bare 'Start date' schema text.

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?

States a specific verb (get) and resource (campaign stats) and then enumerates exactly which results are returned, down to per-step and per-variant breakdowns. It is clearly distinguishable from siblings like list_campaigns, get_campaign_review, and get_setup_status.

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 phrase 'with the same numbers as the dashboard' gives situational context, and the id is traceable to list_campaigns via the schema, but the description offers no explicit when-to-use or when-not-to-use guidance versus get_campaign_review or get_setup_status. Usage is implied rather than stated.

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