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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered. The description adds valuable context beyond annotations: that it reports verification against source and that it surfaces entries these tools exclude with reasons. No return format detail, but no output schema exists, so some burden is on the description.

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 'Headline coverage' and then lists the metrics. It's efficient, though the parenthetical '(with why)' is slightly ambiguous phrasing.

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?

For a zero-param, read-only stats tool with annotations covering safety, the description is essentially complete: it tells the agent what metrics come back, including the verification and exclusion reporting that distinguishes it. Missing only explicit return structure, which is acceptable without an output schema.

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?

Zero parameters, so baseline is 4. Nothing to specify, and the description correctly doesn't waste words on parameters.

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 a specific reporting/aggregation purpose and enumerates the metrics returned: total programs, categories, networks, verified counts, and excluded entries with reasons. It distinguishes itself from sibling tools that fetch individual programs, list categories/networks, or search, though it doesn't explicitly name those siblings.

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?

Usage is implied by 'headline coverage' – an agent can infer this is a summary/overview tool rather than a search tool, but no explicit when-to-use, when-not-to-use, or alternative routing is stated. Siblings like search_affiliate_programs are not referenced.

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