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

With no annotations, the description carries the transparency burden; it clearly discloses the paid nature ($0.01 via x402), the 402 retry behavior, and that no account/signup/commitment is required. It doesn't mention read-only semantics or rate limits, but the disclosed payment/auth flow is significant and actionable.

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?

Core behavior is front-loaded in the first sentence, followed by payment instructions and usage context. The 'BEST COLD START' advice and pitch comparison earn their place; the triple 'no account, no signup, no commitment' is slightly redundant but not bloated.

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 one-parameter listing tool, the description covers purpose, ordering, payment/retry mechanics, and how it relates to `pitch` ('how many' vs 'names'). It does not explicitly address the `scan_bottoms` counterpart, but the top-vs-bottom naming makes that inferable; no output schema is provided, yet the return concept is clear.

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 schema already fully documents the single optional `limit` parameter with default and max, so the description adds nothing necessary. It does reinforce behavior around limiting results but does not need to repeat schema details.

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?

The description names a specific verb ('Scan'), a clear resource ('the commodity complex'), a precise filter ('at a top (sell)'), and an ordering ('ranked most-top first'). It also distinguishes itself from scan_bottoms by direction and from pitch by output (names vs. count), so there is no ambiguity about what the tool does.

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?

It says this is the best cold-start option when no symbol is chosencrazy because it ranks the whole universe, and contrasts with the free `pitch` tool that only gives a count. It doesn't explicitly mention when to prefer scan_bottoms or rate, but the top-vs-bottom distinction and whole-universe framing give an agent enough context to choose correctly.

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