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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral fact beyond the annotations: results are scoped to 'the linked Market Brew account.' It does not describe pagination, ordering, or return shape, so it remains thin.

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 with no padding, and the usage trigger is front-loaded. It is efficient, though the first sentence carries almost no informational weight beyond the tool name.

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-parameter, read-only list tool with full annotation coverage and no output schema, the bar is low and the account-scoping note covers the main behavioral gap. However, given the many sibling list/get tools, the description omits any differentiation or result-size context, leaving it only minimally adequate.

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 zero parameters, which sets the baseline at 4. There is nothing for the description to clarify about inputs, and it correctly does not invent any.

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 verb and resource ('list usage reports'), but it essentially restates the tool name and title without distinguishing it from close siblings like get_usage_report, get_usage_report_history, or get_usage_metrics. An agent can guess the domain but cannot tell exactly what this returns versus those alternatives.

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?

'Use this when the user asks to list usage reports' is circular guidance that just rephrases the name; it gives no conditions, prerequisites, or mention of the get_usage_report / get_usage_metrics alternatives. No when-not-to-use guidance is present.

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