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

The description discloses far more than the annotations alone: the token-overlap matcher, pairing_unverified, the meaning of every compatibility code, the null semantics of temporal_alignment, unclassified leg handling, skipped cross-type/subtype counters, and the fact that Kalshi fees are not modeled so spread_pp is gross. This is exactly the behavioral transparency an agent needs to avoid misusing the 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?

The description is long, but it is organized into clearly labeled sections and every major block adds operational or safety-relevant detail that is not present in the schema or annotations. Some abbreviations and enumerations add density, but the core purpose and mode split are front-loaded, so the structure supports rather than obscures the content.

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 present, the description compensates by explaining the response shape, safety fields, per-entry flags, unclassified and skipped pools, temporal alignment null behavior, fee treatment, and realistic expectations about how often the pre-mapped topics yield tradeable spreads. This gives an agent nearly everything needed to call and interpret 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 coverage is already 100%, so the baseline is 3, but the description adds genuine parameter-level meaning: it treats topic versus explicit fields as a mode choice, explains that explicit fields override the topic-mapped side, and states that both modes run the identical matcher with the same disclosures. It also provides the full shortcut list and concrete example formats for the explicit identifiers.

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 opening sentence clearly identifies the resource: a cross-venue spread between Kalshi and Polymarket for the same resolving question. This is specific enough to separate it from single-venue tools, though it lacks an explicit action verb like 'list' or 'compute' and does not directly distinguish itself from sibling tools such as polymarket_arbitrage or polymarket_edges.

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 defines two invocation modes — pre-mapped topic shortcuts versus explicit kalshi_event_ticker and polymarket_event_slug pairings — and gives practical expectations for each. It also warns that pre-mapped topics do not imply tradeability and that most currently return compatibility warnings, which is strong when-not guidance, though it does not name sibling alternatives.

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