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

Annotations already declare readOnlyHint and idempotentHint true, but the description adds two valuable behavioral details: the endpoint is a paid $0.01 x402 route and the HTTP method is GET. It still omits return format details, but the cost disclosure is significant beyond annotations.

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 two short, front-loaded sentences with no wasted words. It efficiently conveys purpose, endpoint, and cost, though the endpoint fragment is slightly cryptic and could be clearer.

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 simple read-only tool with no output schema, the description should clarify what the returned odds look like (e.g., decimal, implied probability). It does not, leaving a gap in understanding the return values.

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%, with both parameters fully documented in the input schema. The description only reiterates the ‘q’ parameter indirectly via the endpoint URL and adds no new semantic meaning, so the baseline of 3 applies.

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 specific resource (‘Live YES/NO odds for a named Polymarket market’), which clearly differs from siblings like get_polymarket_book or get_polymarket_history. However, it does not explicitly name or exclude any sibling tool, leaving differentiation to inference.

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 offers no guidance on when to use this tool versus alternatives. It merely states what it does (‘Live YES/NO odds…’) without any when-to-use or when-not-to-use context relative to the other polymarket tools.

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