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

Annotations already declare read-only, idempotent, open-world, non-destructive, so the safety profile is covered. The description adds genuinely non-obvious behavior beyond that: account-dependent access/delay/metered usage, a single bounded request with no polling or auto-retry, exclusion of affiliate 27, and no wagers/account changes. This is meaningful disclosure, though the odd 'Product data or price calculation' line adds no behavioral value.

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?

Purpose is front-loaded, which is good, but the rest is a run-on of stitched-together boilerplate fragments ('Read-only Product data or price calculation') and clauses of uneven relevance. It reads like concatenated spec tags rather than a curated description; several phrases do not earn their place.

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 not be explained. The description covers auth/usage context, the empty-result caveat, and the bounded single-request nature. The main gap is sibling differentiation against v2GetMarketsByDate and v2GetAvailableMarketsByEvent, which an agent needs to route 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?

The description adds nothing about parameters; its only parameter-adjacent statement ('Use returned canonical IDs') concerns outputs. The input schema itself does document sportID (with common value table) and offset (UTC minutes), which conflicts with the reported 0% coverage, but judged strictly against the description text it contributes no semantic meaning 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?

The first sentence gives a specific verb and resource with scope ('available markets for a sport and date'), which is enough to distinguish it from event-scoped siblings like v2GetAvailableMarketsByEvent. However, it never distinguishes itself from the very close sibling v2GetMarketsByDate, and the trailing 'Product data or price calculation' fragment muddies rather than sharpens the purpose.

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?

It gives downstream guidance ('Use returned canonical IDs') and a real caveat ('never infer coverage from an empty result'), but there is no explicit when-to-use versus the many market/odds siblings (v2GetAllMarkets, v2GetMarketsByDate, v2GetAvailableMarketsByEvent). Usage is implied rather than stated.

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