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

With no annotations, the description carries the full burden and does well: it discloses data sources, that values are derived and attributed, that freshness is tied to the collector batch, and the x402 payment flow including what happens on unpaid calls. It omits edge-case behavior such as what is returned when no matched pairs exist.

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?

Purpose is front-loaded in the first clause and the usage guidance follows immediately. The only waste is the payment cost stated twice ('$0.02 per call' appears in both the body and the bracketed payment note).

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 no output schema, the description usefully summarizes the return payload as per-pair gaps plus a max disagreement, and it explains cost and freshness. It does not state that the call is unconditional and returns the full pair set with no way to scope to a single market, which an agent would want to know before paying.

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 tool takes zero parameters, so there is nothing for the description to disambiguate beyond confirming the call is parameterless. Baseline for a no-param tool 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 names a specific verb+resource: cross-venue disagreement between Polymarket and Kalshi implied probabilities for matched questions, returning per-pair gap and max disagreement. It is distinguishable from siblings like curade_polymarket_odds because it is explicitly comparative rather than a single-venue price read.

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?

It gives concrete when-to-use conditions: getting a second opinion before acting on a Polymarket signal, or detecting cross-venue mispricings. It does not explicitly say when NOT to use it or name curade_polymarket_odds as the fallback for single-venue pricing, so the routing guidance is clear but not exhaustive.

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