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

Annotations already establish readOnly, idempotent, and closed-world behavior, so the description is not required to cover safety. It adds genuinely new operational context: the 7-day measurement window and a refresh cadence of 'every few minutes', which tells the agent the figures are near-real-time rather than a historical archive.

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?

Two short sentences, front-loaded with what is returned and followed by the freshness caveat. Every clause carries information; nothing is redundant with the name, title, or annotations.

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?

An output schema exists, so return structure need not be described. Combined with annotations covering the safety profile, the description supplies the remaining essentials: metric definitions and data recency. Only the when-to-use routing is left implicit.

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?

The tool takes no parameters, so the baseline is 4. The description correctly uses its space to define the data scope (7-day window, 'verified active') instead of inventing parameter semantics that don't exist.

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 ('BarterBanner network') and the three specific metrics returned (active member sites, active member campaigns, card impressions), which is enough for an agent to distinguish it from list_members or check_site. It lacks an explicit verb like 'retrieve', but the content is unambiguous.

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 sibling tools (check_site, list_members, how_it_works), nor any stated preconditions. The agent must infer that this is the aggregate-stats entry point from the description alone.

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