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

Annotations already cover readOnly, idempotent, non-destructive, and open-world behavior. The description adds genuinely useful operational context: metered usage follows the connected account, no background polling or automatic retry, affiliate 27 is excluded, and empty results do not mean no markets exist. That is real disclosure beyond 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?

It is front-loaded and clear, but the sentence fragments are choppy and mix purpose, data provenance, usage constraints, and legal disclaimers in a dense run-on. Several clauses (affiliate exclusion, wager disclaimer) are only loosely tied to the tool's core function.

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 the description need not explain return values, and it correctly points to canonical IDs. It covers the key behavioral caveats for a metered, read-only market lookup, though it does not address the required path.date boundary or the relationship to sibling market-list endpoints.

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?

Only one of two parameters (offset, backing a required path.date) is documented in the description, and the schema itself documents offset well (UTC-offset-in-minutes with example values). The description adds no path.date formatting or timezone-boundary detail, so it largely rests on the schema's existing coverage.

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: returns available market definitions for each sport on a given date. It is distinguishable from siblings like v2GetMarketsBySportAndDate by being date-only, though the description never explicitly names or contrasts with that sibling.

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 ('Use returned canonical IDs') and warns never to infer coverage from an empty result, but it does not say when to prefer this tool over v2GetAllMarkets, v2GetMarketsBySportAndDate, or list_markets. Guidance is implied rather than explicit.

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