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

With readOnlyHint and openWorldHint already declared, the description adds genuinely useful context beyond annotations: a per-call price ($0.003 USDC) and a result cap (top 10). It does not mention behavior on zero matches or latency, but the cost and cap disclosures are meaningful additions.

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?

A single sentence that front-loads the critical pricing fact and then lists returned fields. Very little waste, though it is a fragment that could name its action verb more explicitly.

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?

No output schema exists, and the description compensates by enumerating the return fields and the top-10 cap, while annotations cover the safety profile and the schema covers both params. Payment mechanics (api_key vs x402) are left to the schema, which handles them adequately.

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 both q and api_key are fully documented in the schema, and the baseline is 3. The description restates keyword matching but adds no syntax, formatting, or matching-rule detail beyond what the schema 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?

The description names a specific resource (Polymarket markets) and the exact payload returned (YES probability, 1h/24h/7d odds change, volume, liquidity, top 10). It is distinguishable from siblings like lookup_coin or lookup_yields, though it is phrased as a noun fragment rather than an explicit verb+resource statement.

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 guidance on when to choose this tool over the free siblings (free_crypto_top10, free_defi_top_yields) or how to phrase the keyword. Usage is only implied by the keyword-matching phrasing; no exclusions or prerequisites are stated.

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