Analyze advanced stats for multiple players

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

Beyond the readOnlyHint annotation, the description discloses the response structure ('mlbStats.columns names the aligned values in mlbStats.standard and the optional mlbStats.recent14d and mlbStats.recent30d arrays') and the authentication context. This gives the agent a clear picture of what to expect without an output schema.

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 compact sentences with key information front-loaded: purpose, usage trigger, and data structure. No filler or redundancy.

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?

Even without an output schema, the description explains the return value layout (columns and arrays) and gives usage context, plus the readOnly annotation covers side effects. It is sufficient for an agent to select and invoke the 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?

The schema already explains both parameters fully (season default, playerNames source and max items). The description adds no new parameter meaning; it only restates 'up to 10 players' and 'full player names,' which are already in the schema. With 100% schema coverage, the baseline 3 is appropriate.

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 a specific verb 'Fetch' and names exact resources ('MLB Stats, Baseball Savant, and FanGraphs analysis') with a clear scope ('up to 10 players'). This distinguishes it from the singular sibling 'analyze_player_stats' and clearly states the tool's purpose.

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 explicitly states when to use the tool: 'Use this after reading roster or free-agent names from the signed-in Yahoo browser.' However, it does not name alternative tools or exclusions, so it stops short of a full 5.

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