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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds non-obvious traits the annotations cannot convey: relative cost (25 cr), the grouping/shape of the result, and a policy boundary on what the agent must never compute from prices.

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?

Four short sentences, each load-bearing: usage trigger, return shape, cost and cheaper alternative, policy constraint. The routing information is front-loaded before the cost comparison.

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?

An output schema exists, so return values need no explanation, and annotations carry the safety profile. The description fills the remaining gaps an agent needs (when to call it, cost relative to the alternative, and the betting-advice prohibition).

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% and both parameters (game_id, bookmaker) are documented there, so the baseline is 3. The description adds no format, casing, or defaulting guidance beyond what the schema already provides.

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?

Specific verb+resource: it returns time-series snapshots of betting line movement grouped by bookmaker. It distinguishes itself from the sibling get_odds by naming that tool and the condition that selects it, so an agent can route correctly without opening either 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?

Explicit when-to-use ('when analyzing how betting lines moved over time'), an explicit cheaper alternative with its use case ('if you only need current lines, use get_odds'), and an explicit prohibition on downstream betting actions. Nothing is left to inference.

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