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

Annotations already declare readOnlyHint and destructiveHint=false, and the description adds real context beyond them: computed on demand from the execution log, a fixed 14-day lookback, ordering, and the semantic of `dropoff` being null when nothing is bad enough. It also preempts a likely misread by explaining that a large `stopped` count on a flow's first block is normal, which is behavior an agent could not infer from schema or 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?

Front-loaded with the purpose and ordered from output contents to semantics to caveats. Slightly overpacked, with minor redundancy such as 'Read-only' restating the annotation, but nearly every clause supplies distinct information.

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, so the description carries the burden of explaining return values, and it does: funnel stages, stop rates, `dropoff` selection rule and its null case, plus goal counts. Combined with the annotation-covered safety profile and a fully documented parameter, nothing needed to call it correctly 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?

The single parameter is fully documented in the schema, including the app-versus-personal key default and the MCP_APPLICATION_REQUIRED failure mode, so description coverage is unnecessary. The description adds nothing about the parameter, which is the expected baseline at 100% coverage.

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 ('Return the measured conversion funnels') plus precise scope: entry flows only, 14-day window, busiest first. It enumerates the concrete quantities returned (entrants, blocks reached, stop share, dead buttons, goals) and defines 'entry flow' versus flows reached from menus/sequences, which lets an agent separate this from get_flow_analytics 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?

Gives a clear when-not-to-act rule ('Propose nothing when the funnels are healthy or too thin') and a scoping exclusion ('a flow reached from a menu button, a sequence or an operator handoff is NOT measured here'). It does not, however, name a sibling alternative for the unmeasured cases, leaving the routing to inference.

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