Trend analysis over an AGC report

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds the analytical outputs the agent will receive, which is helpful, but it never clarifies whether 'export' writes a file, what the date window actually covers, or any rate/permission constraints.

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 tight sentences, front-loaded with the core action and followed by the overview tip. Every clause carries information; no filler or restated name/title.

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 9-parameter tool with an undocumented nested 'filters' object and no output schema, the description does partially compensate by describing the returned trend components. However, it leaves the filters structure, groupBy behavior, and site/language effects unexplained, so it is adequate rather than 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?

Schema coverage is 56%, and the description only elaborates on 'metric' (substring match, empty for overview) — semantics already present in the schema. The undocumented 'filters' nested object, 'groupBy', 'site', and date defaults get no additional explanation in the description.

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 specific verbs (export + analyse) and resource (an AGC report metric), and enumerates exactly what is computed: WoW change, 7-day moving average direction, z-score anomaly days, peak/trough, 28-day sparkline. It does not explicitly name the sibling it differs from (agc_report_export, agc_daily_report, agc_weekly_report), so an agent must infer the boundary.

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 one useful invocation tip — use metric="" for a compact overview of all numeric columns — which is genuinely actionable. But it offers no when-to-use guidance relative to agc_report_export or the daily/weekly report tools, nor any prerequisites or date-range considerations.

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