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

readOnlyHint and openWorldHint are already declared, so safety is covered. The description adds genuine behavioral context by enumerating what the response omits (Kalshi prices, fees, depth, venue ranking, savings), which steers the agent away from assuming it gets a full cost comparison. This negative disclosure is more valuable than repeating the annotation.

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?

Three short sentences, front-loaded with the action. Each sentence carries weight: the first states the output, the second bounds it, the third points to where full comparison lives. No filler, though the negative list is slightly dense.

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?

An output schema exists, so return-shape explanation is unnecessary, and the read-only/open-world annotations cover the safety profile. The description adds the crucial scope caveat that this is not a full cross-venue comparison, leaving the definition sufficiently complete for an agent to call it 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 100% with all four params documented (side, amount_usd, kalshi_ticker, polymarket_id). The description adds no syntax or format detail beyond the schema, so the baseline 3 for schema-covered parameters 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?

States a specific verb ('Return') and resource ('the Polymarket quote for one pair'), plus the secondary returns (Kalshi ticker and notice). The negative scoping ('No Kalshi prices, fees, depth, venue ranking or savings') effectively distinguishes it from richer comparison siblings like compare_platforms or find_best_price, though no sibling is named.

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?

Usage is implied rather than stated: by declaring what is NOT exposed and that comparisons live only on the external web page, the agent can infer this tool is a narrow quote-fetcher and that richer comparison tools exist. There is no explicit when-to-use or named alternative, leaving the agent to infer routing.

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