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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the description earns credit for adding traits annotations cannot express: quotes are compact/summary-level, carry a spread, and go stale, requiring a get_market refresh before acting. That freshness caveat is genuinely useful and not derivable from structured fields.

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?

Two short sentences with zero filler, front-loaded with purpose and ending on the operational caveat. Every clause carries information.

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?

With an output schema present, return-format detail is unnecessary, and the description supplies the remaining essentials: scope, filters, and the staleness/refresh requirement. The only minor hole is the unexplained 'full' parameter, which is small against an otherwise complete picture.

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 coverage is 60% (full and sport are undocumented in the schema). The description maps its three filter axes to league/sport/event_ticker, but says nothing about the 'full' or 'limit' parameters, so it only partially compensates for the coverage gap. Baseline 3 is appropriate.

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 description gives a specific verb and resource ('Browse open markets') plus the filter axes (league, sport, event) and the shape of what comes back ('compact quote rows with a spread'). It differentiates itself from get_market, but not from the similarly-scoped siblings search_markets and screen_markets, which is the main gap.

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 states an explicit follow-up workflow: rows go stale, so call get_market before trading. That is real when-to-use guidance naming an alternative. It does not, however, say when this tool is preferred over search_markets or screen_markets, which are the closest competitors.

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