get_league_matchups

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds meaningful domain context beyond these: it specifies that entries include commissioner-overridden points and that teams sharing matchup_id played one another. This clarifies the data's meaning without contradicting any annotation.

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?

Five sentences, each with a distinct purpose: what it returns, field contents, matchup_id semantics, input sourcing, and use cases. The primary purpose is front-loaded. Slightly longer than necessary but every sentence contributes value, so it earns a 4 rather than a 5.

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 read-only tool with two simple parameters and no output schema, the description covers return contents, input provenance, and intended use cases. It does not mention error handling or empty results, but that is a minor gap for a tool of this simplicity and with strong annotations.

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%, and the schema already tells agents to use get_sport_state for the week and get_user_leagues for the league_id. The description repeats this guidance but adds no new semantic detail. Baseline 3 is appropriate given the high schema coverage.

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 opens with 'Return all team matchup entries for one league week' – a specific verb, resource, and scope. It enumerates the fields returned (roster_id, matchup_id, starters, all players, points, and commissioner-overridden points) and explains the semantics of matchup_id. This clearly distinguishes it from sibling tools like get_league_rosters and get_winners_bracket.

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?

Provides explicit use cases ('Use for weekly recaps, live score summaries, and lineup analysis') and explains how to obtain the required inputs from get_user_leagues and get_sport_state. It does not name alternative tools or state when not to use it, but given no other sibling tool returns matchups, the guidance is clear and sufficient.

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