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

With no annotations, the description does disclose the key non-obvious trait: a $0.005 USDC cost per call, which affects call budgeting. It also frames results as the largest probability shifts within a timeframe. It does not state that the operation is read-only, whether payment is required before results return, or what fields come back.

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 core action and quickly followed by the differentiator and the cost. No repetition or filler; only minor gain would come from cutting the interpretive clause.

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 zero-required-parameter read tool this covers the essentials (what it returns conceptually, cost, timeframe), but with no output schema the description should say more about the shape of each returned market (odds deltas, volume, market id) so an agent can plan downstream use.

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%, so every parameter (limit, category, direction, timeframe, min_volume) is already documented, including defaults and enum-like values. The description only echoes 'timeframe' and adds no syntax or behavioral detail beyond the schema — baseline 3 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 (find) and resource (prediction markets) plus the distinguishing criterion — biggest odds/probability changes. This separates it from prediction_market_odds (quotes) and prediction_markets_trending (popularity/volume trends), though it never names those siblings to make the contrast explicit.

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?

The phrase 'early signal for breaking news or sentiment shifts' implies the use case, so the agent can infer 'use this to detect sudden probability moves.' But there is no explicit when-not-to-use, no mention of competing tools like prediction_markets_trending or prediction_market_arbitrage, and no guidance on choosing a timeframe.

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