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

With no annotations, the description carries the full behavioral burden, and it does disclose two real constraints: the candidate universe is capped at the 500 most-traded active markets, and markets past their end date are excluded. It does not state sort order, whether results are paginated, or that this is a read-only listing.

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 short sentences, front-loaded with the core purpose and followed by the one exclusion rule that matters. No filler and nothing 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 four-parameter tool with no annotations, no output schema, and 0% schema description coverage, the description leaves too much unspecified: result ordering, the direction enum's effect, the limit cap of 50, and how min_volume_24h interacts with the '500 most-traded' universe.

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 for all four parameters. It explains only the window values ('1h, 1d or 1w'); limit, direction, and especially min_volume_24h (default 10000) are never addressed, and the volume filter is not even implied by the '500 most-traded' phrasing.

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 resource and scope: 'Biggest price moves among the 500 most-traded active Polymarket markets.' That is concrete enough to separate it from top_markets (volume ranking) and market_snapshot (single market state), though it never names a sibling explicitly.

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 and no mention of alternatives among the five sibling tools. The window universe ('500 most-traded') and the expiry exclusion hint at scope, but an agent is left to infer when this tool is the right pick over top_markets or search_markets.

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