espnfantasy_matchups

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

The annotations already mark the tool as readOnly, openWorld, and idempotent; the description adds that authentication is optional and that setting ESPN_FANTASY_COOKIE 'unlocks more'. It also details the return JSON structure, providing transparency about what the tool will output.

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 relatively brief but includes multiple components: purpose, return schema, example, auth, and a sibling pointer. The 'Also answers this' line is ambiguous and could be omitted or clarified, and the example could be more integrated.

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 compensates by showing the return structure with example fields like winner, home, away, and pointsByScoringPeriod. It covers auth and gives an example call. However, it doesn't mention potential limitations such as whether playoff matchups are included or how to handle a full season's data size.

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 already documents all four parameters with 100% coverage, so the description's example with concrete values (ffl, 2018, 1234) is helpful but not necessary. It does not add significant new meaning beyond what the schema provides, hence a baseline score.

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 states 'Full season schedule of head-to-head fantasy matchups with each side's total and per-period points,' clearly indicating the tool returns a comprehensive matchup schedule. It distinguishes itself from espnfantasy_matchup_score or boxscore by focusing on the full season schedule. However, it lacks a direct verb like 'get' or 'list', making it slightly less explicit than ideal.

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 includes a pointer to 'sleeper_matchups, sleeper_playoff_bracket' under 'Also answers this,' suggesting alternatives for the Sleeper platform, but it does not provide explicit when-to-use or when-not-to-use guidance. The example call shows typical use, but the decision framework between this and sibling tools is not fully spelled out.

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