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

Annotations already declare the operation read-only, idempotent and non-destructive, and the description adds useful context beyond that: 'Data refreshes every 30 minutes' (data freshness) and 'Returns DK ids in slot order' (output format). It does not discuss the free-plan lineup restriction's behavior or failure modes, but the annotations carry the safety burden well.

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 the core purpose, then efficiently enumerates format rules, modes, supported options and output/refresh behavior. Dense and largely waste-free, with only minor redundancy in the option list.

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 an 11-parameter tool with no output schema, the description covers formats, modes, supported modifiers, the returned value and data-refresh cadence. It lacks explicit auth/quota notes and edge-case behavior, but is otherwise complete enough for an agent to invoke 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 schema already documents all 11 parameters, setting a baseline of 3. The description goes further by tying the parameters to concrete constraints ('under $50,000', 'at most 4 players from one team', '2 or more games') and clarifying mode semantics that the schema leaves as 'Default gpp'.

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 League of Legends lineups') and names the data source (BankrollSZN projections), cleanly distinguishing it from siblings like invoke_lol_projections and invoke_lol_player_pool. It even spells out the supported roster formats (Classic vs Showdown), so an agent knows exactly what it produces.

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?

Explains both the format choice (Classic vs Showdown) and the game-type choice ('gpp scores the ceiling, cash scores the projection'), giving clear context for when to pick each mode. It stops short of explicitly naming alternative sibling tools or stating when NOT to use this optimizer, so it falls just short of the top band.

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