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

No annotations exist, so the description carries the full disclosure burden. It handles this well by surfacing the payment requirement ($0.01 via x402), the no-account policy, and the retry-with-PAYMENT-SIGNATURE-header behavior on the 402 challenge — exactly the operational traits an agent must know. It also discloses the ranking behavior. Lacks rate-limit or result-shape detail, but the critical behavioral surface is covered.

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?

Purpose is front-loaded in the first sentence. The payment block, cold-start note, and pitch comparison each earn their place and are ordered sensibly. Slightly dense with the payment details mid-description, but nothing is wasted or redundant.

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 paid, ranked-list tool with no output schema, it covers the essential ground: operation, ranking order, payment mechanics, 402 retry flow, cold-start suitability, and sibling differentiation. It does not spell out the per-result return format beyond 'names them', a minor gap given the tool's breadth.

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 100% — the single `limit` parameter is fully documented in the input schema ('How many to return (default 5, max 50)'). Per the baseline rule for high coverage, 3 is appropriate; the description adds no parameter-specific meaning beyond what the schema already provides.

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 ('Scan the US market snapshot and return stocks currently at a top (sell), ranked most-top first'). The 'top (sell)' phrasing plus the sibling name scan_bottoms makes the orientation unambiguous, and the cold-start note ('you do not need to pick a symbol') separates it from symbol-specific tools like evaluate_symbol.

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?

Provides clear usage context: the BEST COLD START framing tells the agent this is the entry-point tool for whole-universe scans, and it explicitly contrasts with pitch ('tells you HOW MANY... this names them'). It does not explicitly say when NOT to use scan_bottoms, but the top/bottom contrast is strongly implied. No explicit exclusions, so not a 5.

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