prediction_markets_polymarket_kalshi_scanner

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

With no annotations, the description carries the full behavioral burden. It does disclose that results are real-time and that cross-venue arbitrage is computed across three exchanges, which is genuine value. However it says nothing about API-key requirements, per-venue rate limits, failure behavior when a venue is unreachable, or whether arbitrage detection is cross-venue or intra-venue — significant gaps for a multi-source aggregation tool.

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 front-loaded sentence that names the verb and then enumerates the returned metrics and venues without filler. It is dense but readable; the only deduction is that the venue list at the end could be trimmed since the sources parameter already enumerates them.

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?

With four optional parameters, 100% schema coverage, and no output schema, the description's enumeration of returned fields (probabilities, odds, volume, liquidity, arbitrage) usefully compensates for the absent output schema. It falls short only on operational context such as availability of the venues and the shape/limits of the response.

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 all four parameters (keyword, sources, maxResults, minVolumeUsd) are already documented, establishing a baseline of 3. The description adds only indirect meaning — it confirms the venue list and implies volume/liquidity are first-class fields — but does not explain how keyword matching works, whether sources accepts partial names, or how minVolumeUsd is measured.

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?

States a concrete verb ('Fetch') and a concrete resource (real-time implied probabilities, yes/no odds, volume, liquidity, arbitrage) and names the three venues. The purpose is unmistakable and no sibling tool covers prediction markets, though the description never explicitly contrasts itself with alternatives. Minor inconsistency: the tool name advertises only Polymarket/Kalshi while the description correctly adds Manifold.

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 when-to-use guidance, no conditions under which an agent should prefer this over a general market data tool, and no explanation of what 'arbitrage opportunities' means in this context. The only implicit cue is 'real-time', which suggests freshness-sensitive tasks but gives no exclusions or prerequisites.

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