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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds two traits they don't cover: results are filtered to unplayed future games only, and each call costs 2 credits. Return shape is left to the output schema, and no pagination or rate-limit detail is given.

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 short sentences, zero filler, and the primary trigger ('Use when checking what games are coming up') is front-loaded ahead of scope, alternative, and cost.

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 describing returns, full annotation coverage of the safety profile, and complete parameter documentation, the remaining things an agent needs — the future-games filter, the sibling to use for history, and the credit cost — are all stated. Nothing material 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 description coverage is 100% — all three parameters (days, team, league) are documented including the enum values and default. The description's only parameter-adjacent note is the 7-day default, which the schema already states, so it adds no meaning beyond the structured fields.

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 resource (games schedule) and a precise scope constraint: 'only unplayed future games for the next N days (default 7)'. It also names the sibling it is not (get_games for past games), so the agent can distinguish it 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?

'Use when checking what games are coming up' gives a clear use context, and 'For past games, use get_games instead' supplies an explicit alternative with its selecting condition. It does not address the boundary with get_game_detail (single-game detail), so the routing is strong but not exhaustive.

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