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

Annotations already establish readOnlyHint and openWorldHint, yet the description adds real behavioral context: profit is not locked unless every listed bet is accepted, odds/stake limits/settlement rules can differ, and a missing feed key yields an explicit disabled result rather than invented prices. It stops short of auth or rate-limit detail, but the disclosed caveats are meaningful.

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 purpose, then the algorithm, then caveats and the failure mode. Four dense sentences with no filler, though the statistical rule and the fallback behavior could be tightened slightly.

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 read-only, two-parameter tool with an output schema and covering annotations, the description supplies method, result shape (stakes, worst payout), caveats and the disabled-feed behavior. Only the sibling-routing guidance is absent, which is a minor omission given the output schema carries return detail.

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% (sport_key, capital_usd both documented with defaults), so the baseline is 3. The description reiterates that capital is split across outcomes and returns cent-rounded stakes, but adds no format or constraint detail beyond the schema.

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 (find unfilled sportsbook surebet candidates) plus the exact selection rule (best decimal price per exhaustive h2h outcome, Σ(1/odds) < 1). This is precise enough to distinguish it from siblings like list_arbitrage_candidates and list_executable_opportunities without opening their schemas.

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 context is implied through 'unfilled ... across the configured live books' and the disabled-feed caveat, so an agent knows the precondition. However, it never states when to prefer this over adjacent siblings such as list_arbitrage_candidates or compare_executable_quotes, leaving the routing decision to inference.

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