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

Annotations already declare readOnly/idempotent/non-destructive/openWorld=false, and the description adds non-schema behavior: a 2-credit cost and a policy that prices are market information only, forbidding bet recommendations or stake math. Return-value shape is covered by the output schema, so these additions are exactly the extra context needed.

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?

Three tight sentences, front-loaded with purpose and scope, then the alternative, then cost/policy. Every clause carries information (scope, cost, forbidden actions) with no filler.

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?

Complete for a read-only query tool: purpose, scope, default window, sibling routing, credit cost, policy constraints, and an output schema to describe return values. Nothing an agent needs to invoke it correctly is missing.

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 67%; team and league are already documented in the schema, but the description adds the missing semantics for days — the 1-30 range and the default of 7, which the schema does not state. That directly compensates for the one under-documented parameter.

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 ('upcoming games') plus the exact scope (next 1-30 days, default 7) and the data returned (median line: moneylines, run line, total). It names the sibling it is not — 'For every book's line use get_odds' — so an agent can distinguish it from get_odds and get_games without opening any schema.

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?

Explicitly states when to use it (upcoming games within a 1-30 day window) and names the alternative (get_odds) with the condition that selects it (per-book lines). It also states a hard usage constraint: never compute stakes/payouts, recommend a bet, or refer to a sportsbook.

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