Wheel picker (random pick)

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

Beyond the readOnlyHint annotation, the description discloses real behavioral detail: crypto randomness with rejection sampling, trimming and 100-character truncation of entries, a 500-entry cap and 2-entry minimum, and the seed's reproducibility semantics. This is exactly the kind of constraint an agent cannot infer from structured fields. The seed case is a slight nuance against idempotentHint=false but is consistent for unseeded calls, so it is not a contradiction.

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 core action and its variants come first, with fairness and constraint details following; almost every clause carries information. The parenthetical nesting makes it a slightly dense single run-on sentence, but there is no filler.

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?

There is no output schema, and the description implies but does not state the shape of the return value (selected winners vs. reordered full list). Input constraints, randomness guarantees and the seed behavior are otherwise well covered for a 5-parameter, all-optional tool.

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; the description earns above that by adding semantics the schema lacks — the trimming/truncation of entries, the minimum of 2 entries, and the fact that count removes each winner before the next draw. It does not explain how 'text' and 'items' interact when both are supplied, which is the one ambiguity left.

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 uses a specific verb+resource pair ('Pick a random winner... from a list of names') and enumerates the three operating modes (pick, shuffle, sort), so an agent can tell exactly what the tool produces. It does not name any sibling it should be preferred over (e.g. random_teams, secret_santa_draw, random_dice), so it stops short of full sibling differentiation.

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 clearly states the situations the tool serves: picking one or several winners without repeats, or shuffling/sorting an entire list. The 'remove winner' analogy makes the multi-pick behavior concrete. No explicit when-not-to-use or alternative-tool routing is given.

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