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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile needs no restatement. The description still contributes beyond that by disclosing the full return payload (records, per-season splits, last ten meetings with top players, leaders, next-game projection with chance and margin), which is genuinely useful for deciding whether to call it. It does not mention result size or pagination, so it is not exhaustive.

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?

It is front-loaded: the usage trigger comes first, then the return contents, then the exclusion. The single long enumeration sentence is dense but each item (series leaders, last ten with top player, next game projection) maps to a distinct decision-relevant output, so little is wasted; it would read better split into two shorter sentences.

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?

There is no output schema, and the description compensates by enumerating essentially every returned component, including the next game with projected chance and margin. Combined with the explicit sibling handoff to game_projection, an agent has everything needed to select and call this tool correctly.

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%, with team_a_id and team_b_id already documented as 'from search (e.g. the Celtics)' and league as an enum of nba/nfl. The description adds no parameter-level detail such as ordering behavior between team_a_id and team_b_id or whether the pair must be in the same league, so the schema does all 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?

The description names a specific verb-and-resource ('how two teams have fared against each other') and enumerates the exact outputs: all-time and by-season records, this season's series, last ten meetings with top players, series leaders, and next game projection. It distinguishes itself from game_projection by name, so an agent can route without opening either 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?

It states the triggering user phrasing explicitly with examples ('Celtics vs Knicks history', 'Cowboys Eagles record') and adds a clear exclusion: 'Not for a single game's preview: use game_projection with the game_id it returns.' Both when-to-use and when-not-to-use are given, including the alternative tool and how to obtain its argument.

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