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

Annotations already declare readOnly/idempotent/non-destructive, so the bar is lower, yet the description adds substantial behavior: contest_type loads preset lineup counts (20 for 20max, 150 for 150max), stacks limit hitters against own pitchers, postponed games are removed, and the result carries dk_upload plus a csv in DK's export format. Nothing here contradicts the annotations.

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 purpose then constraints, and essentially every sentence earns its place (roster shape, preset counts, stacking rules, continuation protocol, export format). It is dense run-on prose rather than cleanly segmented, which slightly hurts scanability but wastes no 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?

With 24 parameters and no output schema, the description carries the return-value burden and does: it documents dk_upload, the csv slot order and cell format, and the next_call/remaining pagination fields. For a 24-param optimizer with two enums and nested objects, an agent has everything needed to call and iterate 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?

Schema coverage is 100%, so the baseline is 3, but the description adds real meaning on top: preset-driven lineup counts per contest_type, the 4-2 default stack shape with the primary/secondary concept, and the prior_lineups/total_lineups continuation semantics that the schema only names. A few numeric parameters (min_salary, own_lambda) are left entirely to the 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?

States a specific verb and resource ("Builds DraftKings MLB classic lineups") and immediately fixes the scope: $50,000 cap, BankrollSZN pool, and the exact roster shape (2 P, C, 1B, 2B, 3B, SS, 3 OF). It explicitly differentiates from the closest sibling: "Classic only. For Showdown use mlb_showdown_optimizer."

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?

Names the alternative tool and the condition that selects it (Showdown), and gives an explicit orchestration protocol for large portfolios: when the result has next_call, call again with prior_lineups and total_lineups until remaining is 0, then use the last csv. That is when-to-use guidance the agent cannot infer from the schema.

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