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

With no annotations, the description carries the full burden and does meaningful work: it discloses a per-call cost of $0.002 via x402/USDC (a real gating fact an agent must plan for) and explains that probabilities are shares of free Vpoints with no cash value. It does not cover failure behavior for an unknown or malformed id, nor rate limits.

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 tight sentences, with the capability front-loaded, followed by the cost and then the interpretation of the returned numbers. Nothing is redundant and each sentence adds information an agent needs.

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?

There is no output schema, so the description should say more about the shape of the 'pools' and 'players' data it promises; naming them without describing their structure is thin. Error behavior for a nonexistent market id is also unaddressed, though for a one-parameter read tool the essentials are present.

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?

The single 'id' parameter has 0% schema description coverage, so the description must compensate. 'of one Vatic market' clarifies that the id identifies a market, but it does not say the id is a UUID or where to obtain one, leaving the parameter only partially explained.

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 and resource: fetches 'exact live crowd probability, pools and players of one Vatic market.' The singular 'one Vatic market' implicitly contrasts with the list-style sibling live_markets, but no sibling is named explicitly, so differentiation rests on inference.

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?

'Exact live' implies use for current state rather than history, which quietly points away from market_history, and the stated price is a real decision signal. However, there is no explicit when-to-use/when-not guidance and no named alternative such as get_market or live_markets.

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