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

With no annotations provided, the description carries the full burden of behavioral disclosure. It adds some context through the 'open' filter and 'normalized' qualifier, but does not explain pagination, venue filtering behavior, or what 'normalized' entails. This is a minimal disclosure for a tool with no 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 a single sentence with no filler, front-loading the primary action. However, its brevity omits crucial operational details, making it more under-specified than truly concise. Still, relative to the dimension, it is efficient.

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?

Although an output schema exists, the description remains insufficient for a tool with two unannotated parameters and no tool-level annotations. It lacks information about venue filtering, limit semantics, and the meaning of 'normalized', leaving significant gaps for an agent to invoke the tool correctly.

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 0%, and the description fails to compensate. It never mentions the 'limit' parameter and only indirectly hints at 'venue' by naming Kalshi and Polymarket, without explaining the parameter's format, nullable status, or allowed values. No parameter semantics are provided.

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 clearly states the tool's action ('List'), resource ('open prediction markets'), and scope ('across Kalshi and Polymarket (normalized)'). This specific phrasing differentiates it from sibling tools like get_market (single market) and matching_markets (likely searching/matching).

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 provides no guidance on when to use this tool versus alternatives. It does not mention get_market or matching_markets, nor any exclusions or prerequisites. The only implied use case is listing open markets, but no explicit usage direction is given.

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