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

The readOnlyHint and openWorldHint annotations already establish that this is a safe, free-access operation. The description adds valuable behavioral context by qualifying the free tier: without a key, only the single largest gap is returned, while email/Pro unlocks more. This prevents an agent from assuming open access means full board access.

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 first several sentences are dense and front-loaded with functional information. However, the final sentence about the public track record is promotional rather than operational and does not help an agent select or invoke the tool, so not every sentence earns its place.

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 tool with one optional parameter, read-only annotations, and no output schema, the description is largely complete: it states what is returned, the access-tier limits, and the intended query phrasing. It does not define WATCH versus ARB signals in detail, but the essentials needed to call the tool are present.

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?

The only parameter, minGap, is already fully documented in the input schema, including accepted formats and the default WATCH threshold. The description does not add additional parameter-level meaning, so the baseline score 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 uses a specific verb ('Scan for') and a specific resource ('cross-platform price gaps between Kalshi and Polymarket on the same sports contract'). It lists the exact sports covered and the exact returned fields, making the tool's scope unmistakable and implicitly distinguishing it from generic siblings like scan_mispricings.

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 explicitly lists query phrases that should trigger this tool: 'where is the arbitrage', 'cross-platform price gaps', and 'Kalshi vs Polymarket mispricing'. It does not explicitly state when not to use it or name an alternative tool, but the intended use cases are clear enough for an agent to route correctly.

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