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

Annotations already declare readOnly, idempotent, non-destructive, open-world behavior, so the bar is lower, yet the description adds real operational context: metered usage/delay tied to the account, a single bounded request with no polling or retry, affiliate 27 exclusion, and no wagers or account changes. These are traits an agent cannot get from the annotations.

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 text reads as concatenated fragments ('...for a sport and date Read-only Product data or price calculation.') with no front-loading or logical grouping, and the compliance boilerplate occupies more space than the tool-specific content.

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 the description covers safety, coverage caveats, and the affiliate exclusion. However, it omits the primary selection question — why choose v1 openers over the v2 openers or the closing-lines sibling — leaving an agent to guess on routing.

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?

The schema itself documents sportID (with a full sport lookup table), offset, event_status, and affiliate_ids, so the heavy lifting is done structurally; the description contributes only the affiliate-27 exclusion. It adds nothing about date boundary handling or include/division/conference filtering, so it neither compensates for nor meaningfully extends 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?

The first clause states a specific verb and resource ('Get opening lines for a sport and date'), which cleanly separates it from siblings like v1GetClosingBySportAndDate (closing lines) and the v2 variant. It does not explicitly call out the v1-vs-v2 distinction, so an agent must infer that from the name, but the core purpose is unambiguous.

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?

The description implies usage context ('Use returned canonical IDs', 'never infer coverage from an empty result') but never says when to prefer this over v1GetClosingBySportAndDate or v2GetOpenersBySportAndDate. Guidance is present but implied rather than explicit routing.

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