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

Without annotations, the description carries the full burden. It discloses important behavioral traits: cost ($0.01 via x402/USDC) and data quality (verified outcomes with sources and exact probabilities). However, it omits potential details like rate limits, pagination behavior, or whether authentication beyond payment is required.

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 two sentences, front-loaded with the core purpose and followed by cost information. Every sentence earns its place with no unnecessary wording.

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 simple feed with no output schema, the description should explain the return values more concretely. It conveys the content (verified outcomes, sources, final probabilities) but not the structure (e.g., array of objects, fields) or pagination details. This gap leaves the agent partially informed.

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 67% (since and category have descriptions; limit does not). The description adds a small amount of meaning by mentioning 'any date range,' which loosely relates to the 'since' parameter, but it does not explain the 'limit' or 'category' parameters beyond what the schema already provides.

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 states a specific resource: 'Verified outcomes of resolved Vatic markets with sources and exact final probabilities, any date range.' This clearly identifies the tool's output and scope. It doesn't explicitly name a sibling alternative, but 'any date range' implies a broader scope than a 'recent' feed, providing some differentiation.

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?

There is no guidance on when to use this tool versus alternatives (e.g., recent_resolutions), no exclusions, and no prerequisites mentioned. The description merely states what the tool returns and its cost.

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