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

Annotations already declare this is a safe, read-only, idempotent, non-open-world computation, so the bar is lowered. The description adds one behavioral fact (it flags the biggest drop-off step), but says nothing about what else the model returns or any assumptions/caveats of the funnel math.

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 the core purpose front-loaded and no wasted preamble. The trailing promotional URL is minor padding but does not obscure the description's meaning.

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 no output schema, the description must at least sketch the return surface. It names one output (biggest drop-off step) but omits the overall funnel/activation metrics a caller would expect, so the agent cannot fully anticipate what comes back.

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% and every parameter carries its own description (e.g., step2CompletionPct is explicitly a step1→step2 rate), so the schema does the heavy lifting. The description adds no parameter-level meaning beyond that, which is the expected baseline.

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+resource: 'Model a multi-step product tour funnel from start through completion to activation.' This is a clear, narrow resource (product tour funnel) that separates it from generic siblings like conversion_funnel. It does not explicitly name a sibling or state what distinguishes it, so it falls short of a 5.

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?

There is no when-to-use guidance, no prerequisites, and no named alternatives among the many grader/simulator siblings. The only added pointer is a marketing URL rather than routing guidance, leaving the agent to infer applicability on its own.

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