mfl_league

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

The description enriches beyond the annotations (readOnlyHint, openWorldHint, idempotentHint) by providing auth details ('works without a key; MFL_COOKIE unlocks more if set'), a caveat about variable roster limits, and identifying the key fields in the return (`starters` and `franchises[].id`). It also gives a concrete example, all of which help agents understand behavior and expectations.

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-organized with clear sections (purpose, returns, key takeaway, example, auth). It is somewhat lengthy but each segment provides necessary information, and the use of headings and the 'THE THING YOU NEED' highlight makes it scannable. It is not overly verbose given the complexity of the return structure it describes.

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?

Given no output schema, the description provides a detailed return structure sample, highlights critical fields, explains auth, includes an example, and warns about variability. It covers all essential aspects an agent needs to call the tool correctly, including linkage to other operations (franchise id for writes). The tool is self-contained for making the call.

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 provides comprehensive descriptions for all 5 parameters (100% coverage), including the meaning of L, year, and the read-only nature of APIKEY. The description adds an example request (year and L values) but does not significantly enhance the semantic understanding beyond what the schema already conveys. Baseline 3 is appropriate given the schema coverage.

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 the tool's function: league setup details including roster size, starting-lineup requirements, franchises, divisions, and IR/taxi-squad sizes. It also explicitly says 'it defines what a legal lineup is,' making its purpose unambiguous. Among the many mfl_* siblings, this one is distinct as the configuration/league definition tool.

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 instructs to 'Read this FIRST' and explains that it defines legal lineups, implying it should be called before any lineup-based operations. It also warns that 'roster limits differ per league — never assume a standard shape,' reinforcing the need to always use this tool. However, it does not explicitly mention alternatives or when not to use it, though the context of siblings makes it clear this is the league setup tool.

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