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

Annotations already cover safety (readOnly, idempotent, non-destructive), and the description still adds real context: API key requirement, per-tier rate limiting, sort order (live games first, scheduled after), the ud- id prefix convention, and that count=0 with an empty array is a normal outcome rather than an error.

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 and scope are front-loaded in the first sentence, and nearly every clause carries operational information. The inline return-shape notation is dense but justified because no output schema exists; a few sentences (sort order, workflow) could be tightened.

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 no output schema, the description supplies the full return shape and field meanings (id, live, source), covers the empty-result edge case, states auth and rate-limit requirements, and connects the output to the next tool call. Nothing an agent needs to invoke this 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?

The schema already documents the sport parameter at 100% coverage, including the accepted values and the omit-to-default behavior, and the description largely restates that default. No additional syntax, casing, or normalization guidance is supplied, so the schema does the heavy lifting and baseline 3 applies.

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 precise verb and resource with scope qualifiers: 'Return today's games that have player props available for a sport.' It explicitly separates itself from get_game_props (pass an eventId) and find_game (single-game lookup by team names), so an agent can choose without opening schemas.

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?

Contains explicit 'When to use' and 'When not to use' sections, including the skip condition ('if you already have the eventId') and a named alternative for a specific sub-case (find_game when you know team names). It also documents the downstream workflow with get_game_props.

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