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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context: early access requiring Ultra plan, progress refreshed on its own cycle, omitted fields are never null/empty, settled competitions always served, and no background polling. It also notes affiliate 27 exclusion. This is substantial beyond annotations, though return format details are partly covered by the output schema.

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?

The description is lengthy, with multiple bolded sections and a block of boilerplate at the end. It is front-loaded with the core purpose, but the legal/usage boilerplate ('Read-only Product data... Affiliate 27 is excluded...') is generic and could be trimmed. The detailed explanations of `progress` and `leaders` are useful but verbose.

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?

Given the tool has an output schema, the description needn't explain return values, but it does provide rich context on the event object shape and the optional detail keys. It covers access requirements, refresh behavior, and edge cases (omitted vs null, settled events). It doesn't discuss rate limits or pagination (not applicable for a single resource) but is largely complete for an agent to call correctly.

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 0%, so the description must compensate. It does mention `include_settled` is not a parameter and explains that `sportID` and `eventID` come from prior responses, but doesn't detail the `market_ids` and `affiliate_ids` query parameters beyond what the schema provides (none). The description adds some parameter-related context (e.g., no include_settled) but doesn't fully compensate for the 0% coverage of the two query params.

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+resource: fetches exactly one futures/outright competition event by ID. It explicitly contrasts with the listing endpoint `GET /api/v2/sports/{sportID}/futures` and clarifies that unlike the listing, settled competitions are always served here. This differentiates from sibling `v2GetFuturesForSport` and `list_futures`.

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?

Provides explicit when-to-use guidance: use this for a deep link when you already hold the event ID, as it includes optional detail-only keys (`progress`, `leaders`, `player_leaders`) not served on the listing, and it keeps working after settlement unlike the listing. Names the alternative (the listing endpoint) and the condition distinguishing them.

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