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

With no annotations supplied, the description carries the full burden and does well: it discloses that the call is paid, the exact price and payment chain, that no account or API key is needed, the sort order of results, and the shape of returned fields. It stops short of rate limits, per-call vs per-session billing behavior, or error handling for bad limit values.

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?

Four telegraphic clauses ordered by importance: paywall flag first, then what you get, then sort order and fields, then price/auth, then endpoint. No filler sentences and nothing repeated from the schema.

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 single-optional-parameter paid data tool with no output schema, the description covers cost, authentication, ordering, and return fields, which is what an agent needs before committing USDC. The main remaining gap is guidance on choosing this tool over its many buy_pm_* and buy_polymarket siblings.

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% and the single 'limit' parameter is documented in the schema as markets 1-50 with a default of 10, so the baseline of 3 applies. The description adds no meaning about the parameter beyond confirming that results are volume-sorted, which affects how the limit truncates the list but is not spelled out.

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 a concrete resource and scope: live Polymarket odds restricted to 'openai' markets, plus the sort order (24h volume) and the per-outcome fields returned. It implicitly separates itself from topical siblings such as buy_pm_ai and buy_polymarket by naming the 'openai' topic, though it never explicitly says 'for AI-general markets use buy_pm_ai'.

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 'Paid.' prefix plus '$0.05 USDC on Base. No account, no API key.' makes the cost and access prerequisites clear, which is meaningful usage context. However, there is no explicit when-to-use versus when-not-to-use guidance, nor any routing to sibling tools like buy_pm_ai or buy_polymarket, so selection depends on inference from the topic name.

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