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

Annotations already declare this a safe, closed-world read (readOnlyHint true, destructiveHint false), so the safety profile is covered. The description adds genuinely useful information not in the annotations: it is a paid call at 20 credits / €0.20, which affects whether an agent should invoke it speculatively. Return format is not discussed, though an output schema exists; the stray 'CONVERT.' fragment adds no behavioral meaning.

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?

The core value proposition is front-loaded and the input/cost details follow compactly; little waste. The single capitalized fragment 'CONVERT.' is unexplained noise that costs it a point.

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?

Output schema presence removes the need to explain return values, and cost/input guidance covers the invocation essentials. For a paid, 3-parameter analysis tool the definition is serviceable but incomplete: session_id is undocumented and there is no statement of prerequisites, limitations, or how results tie to follow-up tools like fix_checkout.

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 0%, so the description must compensate, and it partially does: it explains funnel_description (natural-language funnel steps) and funnel_data including the concrete JSON shape {steps: [{name, users}, ...]}, plus that it is optional. However, session_id is never mentioned, leaving one of three parameters unexplained in both the schema and 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 a specific verb and resource: find where and why customers abandon the funnel, with statistically significant per-step drop-offs and the behavioral barrier at each point. That is far more concrete than a name restatement, but it never distinguishes itself from near-neighbors like find_hidden_barriers or predict_churn, which an agent could plausibly confuse with barrier detection.

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?

The 'Input: describe the funnel steps, optionally with data' line tells the agent how to invoke it, which implies the usage context, but there is no explicit when-to-use / when-not guidance and no routing to the sibling tools listed. Adequate but leaves selection between diagnose_dropoff and find_hidden_barriers to inference.

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