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

With readOnlyHint/idempotentHint/destructiveHint already declaring a safe read, the description adds genuinely new context: prices refresh several times a day (freshness expectations) and each price carries the time it was pulled. It does not discuss auth, plan limits beyond the schema's 'plan limit applies,' or pagination, so 4 rather than 5.

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 sentences, front-loaded with what the tool returns, then enrichment (model probabilities), then the routing hint and freshness note. Dense but every sentence carries information; the market enumeration is slightly long but justified for a comparison tool.

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?

No output schema exists, and the description compensates well by enumerating the returned markets, the accompanying BankrollSZN model probabilities, and price timestamps. Only freshness pagination behavior and the meaning of 'plan limit' remain unaddressed, which is minor.

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 schema fully documents limit, market, and fighter, including the enum. The description's list of markets echoes the enum values and adds no syntax or formatting detail beyond the schema, so the 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-and-resource: retrieves DraftKings and FanDuel prices for every bout on the next UFC card, and enumerates the exact markets returned. This clearly separates it from invoke_odds_comparison and invoke_mma_projections, which an agent can distinguish without opening any 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?

Explicitly routes the agent: 'For the best price and expected value per market use mma_fight_sim,' naming the alternative and the condition that selects it. It stops short of stating when NOT to use this tool or how it relates to invoke_odds_comparison, so it falls just short of a 5.

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