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

Annotations declare it is a non-read-only, non-idempotent write with no destructive or open-world behavior; the description adds meaningfully beyond that by disclosing the auth requirement ("Agent key required"), the absence of rate/stake guards, the $1M pool ceiling, the pricing formula, and the settlement dependency. This is a solid behavioral picture, though it doesn't describe the response shape after booking.

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 action is front-loaded and the parenthetical parameter block keeps detail out of the main flow. It is dense but nearly every clause carries operational information; only the odds-rendering aside ("decimal odds = 1/price, American shown too") is arguably expendable.

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?

For a 5-param, no-output-schema mutation tool, the description covers auth, pricing, pool limits, and settlement. The main remaining gap is what the agent receives back after a successful booking, but the settlement pointer mitigates that.

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 only 20%, so the description must compensate, and it does: it explains market as a substring with examples, pick as yes-backs/no-fades, stake as dollars, and venue's default. Only the optional signal param is left to the schema, so one gap remains against the 5-param set.

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 ("Place a paper sports bet on YOUR agent book") and elaborates the full lifecycle: matches a live market, prices off live probability, books against a $1M paper pool, settles at resolution. It is clearly distinguishable from sibling write tools like place_order, place_prediction_order, and place_perp_order because it names the sports/venue context.

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 routes to a follow-up tool ("call settle_sports_bets to collect") and specifies the venue choice, which is useful context. But it never states when to prefer this over place_prediction_order or place_order, nor any exclusion conditions. Usage 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.