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

With no annotations provided, the description carries the full behavioral burden and largely meets it. It discloses freshness-gating ('rows older than ten minutes are withheld and the response says stale'), the regime logic (live vs drift vs none) with concrete definitions, and a disclaimed stance ('a basis is an observation, never a trade'). This goes beyond a typical tool description, though it omits return-format and pagination detail.

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 description is front-loaded with the core purpose and key metrics, which helps. However, it is a single dense block containing intricate regime-definition prose and esoteric phrasing like 'a basis is an observation, never a trade,' which could be trimmed. Informative but not concise.

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 tool with no annotations and no output schema, the description must carry all load-bearing context, and it does: it specifies the per-market fields, the basis block contents, the regime meanings, and the staleness behavior. It is thorough given the tool's complexity, though it omits explicit return-structure and pagination details.

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%, so the lone parameter (stocks_only) is already fully documented by the schema. The description adds complementary context by explaining that markets sharing a ticker with a registered tokenized stock carry the DEX spot price and basis block, reinforcing what stocks_only=true selects. This is a small increment over the schema baseline of 3.

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 states the tool lists perpetual markets on Robinhood Chain (the chain's native perp venue, USDG-quoted) and enumerates the returned metrics: mark, index, open interest, 24h volume, funding rate, settlement time, and, for stock-tickered markets, a basis block. It differentiates itself by claiming 'No other index has both legs,' which helps identify it against siblings. The verb is implicit rather than explicit, but the resource and scope are precise.

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 description implies usage context through 'No other index has both legs,' suggesting this is the only venue to obtain both the DEX spot leg and the basis block. However, it never names alternatives such as the sibling perps_funding tool, nor does it state when NOT to use this tool in favor of another. Guidance is implied rather than explicit.

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