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

Annotations already cover read-only, idempotent, open-world, non-destructive behavior, and the description adds genuinely new context: a per-call price ($0.05 USDC on Base x402) and Ed25519 signing. It also discloses that search is server-side and what fields come back, though it omits rate limits and whether the optional filter defaults to all markets.

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 core purpose is front-loaded and specific, but the pricing is stated twice ('$0.05 USDC x402 Base' and '[x402: 0.05 USDC per call on Base]'), and the inline input example duplicates the schema example. Redundancy costs it points on an otherwise tight description.

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 one-parameter, read-only search tool with annotations covering its safety profile, the description supplies pricing, signing, platform scope, and even the returned field list in lieu of an output schema. Missing only query-syntax guidance and pagination/cardinality expectations.

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% and there is only one parameter, so the schema already carries the semantics. The description's added value is confirming the filter is optional and giving a concrete example, which is marginal beyond the schema.

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 clear verb+resource ('Search prediction markets') and a distinguishing scope ('ACROSS PLATFORMS (Polymarket + Kalshi)'), plus an enumeration of the returned fields. It separates this from a single-platform tool, though it never explicitly names the sibling polymarket_trades it most overlaps with.

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?

Gives a target audience ('For trading and forecasting agents tracking event odds') and example query terms (bitcoin, fed, election, geopolitics), which implies when to reach for it. It offers no explicit when-not condition or named alternative, so routing versus polymarket_trades is left to inference.

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