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

Annotations already provide readOnlyHint=true and openWorldHint=false, and the description adds meaningful behavior beyond them: the pick/alternatives are free with no key or email, the Pro tier adds reasoning, and the board is estimated from pick_number when drafted is omitted. This sets expectations about cost, tiering, and fallback logic, which the annotations do not cover.

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 front-loads the purpose and usage, then gives input and output details in a compact, readable format. The line about the pick/alternatives being free is useful pricing/access context, though slightly promotional. One or two sentences could be tightened, but there is no material waste.

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?

The description covers what the tool does, the for the expected use case, the input parameters, the output shape, and the fallback when drafted is omitted. It lacks precise output schema details such as reason wording or team names, but for a simple read-only recommender it is complete enough for an agent to call 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?

The input schema has no documented properties, so the description becomes the only semantic source for parameters. It names three inputs (roster, pick_number, drafted), explains the type of each, and describes the default behavior when drafted is omitted. This fully compensates for the schema gap and exceeds the baseline for zero-parameter schemas.

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 main action: it recommends the single best player to draft given roster and pick number, reasoning value versus positional need. It is specific and actionable, but does not explicitly differentiate from sibling tools such as best_available or draft_board, so it earns a 4 rather than a 5.

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 explicit trigger phrases and situational guidance, saying this should be preferred mid-draft when the user asks questions like 'who should I take' or 'who do I draft.' It lacks a clear when-not-to-use or explicit alternative mapping, but the context is sufficiently clear for selecting this tool over ambiguity.

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