Get User's Leagues

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

Annotations indicate readOnlyHint, idempotentHint, and destructiveHint false. The description adds value by specifying the return format (list of leagues with fields) beyond what annotations provide. No contradictions.

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 well-structured with a summary, Args, Returns, and Examples sections. Every sentence is informative, and the format is easy to parse.

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 simple query tool with three parameters, the description covers all necessary aspects: purpose, parameter details, return structure, and usage examples. No output schema needed as return is explained.

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%, meeting baseline. The description adds meaningful context: for user_id, suggests using sleeper_get_user; for sport, states default 'nfl'; for season, provides example years. This enhances agent understanding.

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 'Get all fantasy leagues a user is in for a given sport and season,' specifying the verb, resource, and scope. It lists parameters and return fields, distinguishing it from siblings like sleeper_get_league.

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 clear context for when to use the tool, including a hint to use sleeper_get_user for user ID lookup. It does not explicitly state when not to use, but examples and parameter details make the usage clear.

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