Build a weekly AGC report with WoW comparison (Markdown)

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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so safety is covered. The description adds two genuinely useful facts beyond that: the previous week is fetched automatically (an extra round trip the caller should expect) and Markdown is optionally written to outPath, a local side effect worth flagging. It says nothing about auth requirements, latency from the multi-report aggregation, or failure modes.

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?

Three tight sentences with the purpose and time window front-loaded, followed by output content and the optional write. No filler; the only slight inefficiency is that defaults already documented in the schema are restated.

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?

With nine parameters, 44% coverage, and no output schema, the description does meaningful work: it names the three returned sections, states the returned format (Markdown), explains the automatic prior-week fetch, and covers the outPath side effect. Remaining gaps are crashKind, countries, and overwrite, which an agent must infer from the 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?

Schema description coverage is only 44%, so the description must compensate, and it partially does: it explains the date window semantics of endDate and the optional write behavior of outPath, and its section list hints at the report/crashKind/platform roles. But site, countries, overwrite, and the wide report enum are left for the schema alone, leaving a real gap.

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 and resource ('Build a weekly digest') plus exact scope: the 7 days ending on endDate, with three named sections (download/install totals, crash totals, review keywords). 'Weekly' implicitly distinguishes it from the sibling agc_daily_report, but no sibling is named explicitly, so it falls short of full differentiation.

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?

Gives clear operating context: the 7-day window ends on endDate (default yesterday) and the previous week is fetched automatically for the WoW comparison. However it never states when to prefer this over agc_daily_report, agc_report_trend, or agc_report_export, so the routing guidance is only implied rather than explicit.

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