List probable starting pitchers for a date

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

Discloses source (MLB Stats API), no auth needed, explains data availability pattern (not an error for empty results), and warns about per-starter Yahoo requests. This goes well beyond the readOnlyHint 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?

Front-loaded with main action and output, then details. Slightly lengthy but every sentence earns its place with useful information. No wasted words.

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?

No output schema, but description outlines return fields (opponent, home/away, start time, optional fantasy context). Explains data limitations. Sufficient for a list tool with two parameters.

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 coverage is 100%, so baseline is 3. The description adds meaningful context: date parameter's typical range and behavior for future dates, and fantasyContext's enrichment cost and value. Adds extra clarity beyond schema.

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 'list every probable starting pitcher across MLB for a date' with specific details (opponent, home/away, start time). This distinguishes it from sibling tools like search_players or get_player_stats, which serve different purposes.

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 guidance on when data is available (today through ~2-3 days out) and advises against using fantasyContext unless needed due to enrichment cost. No explicit alternatives to other tools, but the context signals include a sibling list.

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