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

Beyond the annotations (readOnly, openWorld, idempotent, non-destructive), the description discloses the authentication requirement, the fact that the user is not currently signed in, the expected auth challenge, and the instruction not to fabricate. This is valuable behavioral context.

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?

The description is front-loaded with the core purpose and then provides essential auth guidance. It is somewhat verbose with repeated 'Data Licensee tier' mentions and a long auth explanation, but each sentence adds value.

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?

Given no parameters and no output schema, the description covers the key contextual aspects: what the tool does, the auth requirement, and the expected behavior (challenge prompt). It could explain what happens after successful auth, but it is largely complete.

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 input schema has zero parameters, so schema coverage is trivially 100%. The description doesn't need to add parameter details. Baseline for 0 params is 4, and no additional parameter description is necessary.

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 states a specific action and resource: 'Aggregate PCI staff-training coverage trends' with detailed metrics (completion, pass rate, delivery mix, expiry). It clearly distinguishes itself from sibling tools by focusing on training coverage and Data Licensee tier.

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 description provides clear context for when to call: 'if the user is asking for their own business, reseller, or licensed data'. It does not explicitly mention alternatives or exclusions, but the conditional guidance is strong enough for an agent to know when to proceed.

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