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

Annotations already declare the safe read profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the description's added value is the plan gating and the key staleness disclosure that the data comes from a cache snapshot rather than live API. That is genuinely useful behavioral context an agent could not infer from the annotations.

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 sentences with zero filler; the plan requirement and cache-vs-live caveat are front-loaded rather than buried. Every clause earns its place.

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?

There is no output schema, but the description explicitly enumerates the returned metrics, so the agent knows exactly what it gets back. Combined with the plan gate, time-window scope, and cache caveat, nothing needed to call or interpret the result is missing.

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 100%, including the startTime default of '7 days ago', so the schema already documents all four parameters. The description only says 'over a time window' and adds no format or semantics beyond the structured fields, matching the baseline 3 when the schema does the heavy lifting.

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?

Specific verb+resource ('Get aggregated run statistics for a flow') with an enumerated list of the exact metrics returned (runs, success/failure counts, rates, avg/max duration). The 'aggregated ... from the cache' framing lets an agent separate this from raw-run siblings like get_store_flow_runs without opening either schema.

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?

Clarifies the data source boundary ('stored snapshot — not live from the Power Automate API'), which implicitly routes the agent to live-API siblings when freshness is needed, and states a prerequisite ('[Requires Pro+ plan]'). It stops short of naming the alternative tool explicitly or stating when-not-to-use beyond the staleness caveat.

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