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

Annotations already declare readOnlyHint and non-destructive, and the description reinforces this while adding substantive context beyond the annotations: result cardinality (up to 10, default 5), outcome-selection ordering logic, inclusion of 24h change and volume, and the caveat that probabilities are crowd forecasts, not advice.

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?

Front-loaded with the core trigger and the tool's output shape, with exclusions at the end. The eight worked examples are genuinely useful for routing but take considerable space; the definition could be trimmed without losing clarity.

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 two-parameter, read-only search with an output schema and full annotation coverage, the description covers triggers, output shape, sibling routing, and safety caveats. Nothing an agent needs in order to call it correctly is missing.

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 100%, so the baseline is 3: the schema already documents both parameters, including the default of 5 for limit. The description adds modest value by clarifying the query should be an event/person/team/asset in plain words and by implicitly linking named outcomes to result ordering.

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 (search) and resource (Polymarket prediction markets), and explicitly distinguishes itself from the sibling that handles deep single-market lookups (get_market_odds). An agent can route between the two without opening a schema.

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 concrete trigger phrases ('odds', 'chances', 'what does the market say'), names the alternative for a different need (get_market_odds for full outcome lists, rules, resolution status), and states two explicit exclusions: don't use it to pick a market to buy or to advise on profit.

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