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

With no annotations, the description carries the full burden, and it does contribute real behavioral context the schema cannot: a per-call cost of $0.01 via x402/USDC and the sampling cadence. It omits how the x402 payment is actually satisfied, whether repeated calls bill again, rate limits, and pagination or result-size behavior for a potentially long history.

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 tight sentence with the resource and scope front-loaded and the cost detail appended. Nothing is redundant or wasted.

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?

Given one required parameter, no output schema and no annotations, the definition supplies the two things an agent most needs before calling: what it returns (full timestamped probability history, one point per call) and that it is paid ($0.01, x402/USDC). Return-value explanation is unnecessary since granularity is stated.

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 0% – the lone 'id' parameter is documented only as a UUID pattern with no description. The phrase 'one Vatic market' does clarify that id is a market identifier rather than a user or question id, which is genuine added meaning, but nothing is said about invalid-id handling or whether the full history is returned unbounded.

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+resource: 'full timestamped probability history of one Vatic market', with the sampling granularity '(a point after every call)'. This implicitly distinguishes it from snapshot-style siblings like get_market, live_market and market_summary, though it never names them.

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 only implied: 'history' versus a current snapshot suggests when to pick it, and the per-call point granularity hints at time-series use. There is no explicit when-to-use, when-not-to-use, or named alternative, so the agent must infer the routing decision.

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