espnfantasy_matchup_score

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

The annotations already declare readOnlyHint, openWorldHint, and idempotentHint, so the bar is lower. The description adds auth details (works without a key, ESPN_FANTASY_COOKIE for more), the return shape, and the fact that it returns only totals, not lineups. This extra context goes beyond the annotations without contradicting them.

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?

The description is compact and front-loaded with a clear summary. It includes return format, an example, and auth note in a structured way. The 'Also answers this' line is a bit cryptic but does not significantly bloat the text.

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 tool with no output schema, the description provides the return structure, an example request, and auth requirements. It does not explain error cases or pagination, but given the simple nature of returning compact season totals and the 100% schema coverage, this is reasonably complete. The cross-reference to sleeper tools adds a broader answer context.

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 input schema has 100% description coverage, so the baseline is 3. The description adds a concrete example call with game, seasonId, and leagueId, which clarifies how the required parameters are used together and reinforces the default for game. It doesn't add much detail for optional filters, but the schema covers those adequately.

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 clearly states that the tool returns compact matchup scores for the season, totals only, without lineups, and explicitly contrasts itself with the box score. It also names sibling tools (sleeper_matchups, sleeper_playoff_bracket) it can answer for, helping distinguish from other ESPN tools. This is a specific verb+resource+scope description.

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?

The description provides context for when to use this tool: when you need compact season matchup totals rather than full box scores or lineups. It mentions an alternative (box score) and even cross-references sleeper tools, but does not explicitly state when not to use it or outline an exclusion rule. The guidance is clear but not fully explicit.

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