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

Beyond annotations, it discloses concrete state effects: it opens a clue, only opens the final once the board is clear, gives up the open clue on "skip", closes a survey question after three strikes with "no steal", deals the first card in a timeline game, and sets up rules/players. This is rich behavioral context for a non-read-only, non-idempotent tool.

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 purpose is front-loaded, but the description is a single dense paragraph with nested parentheticals and mode-specific clauses that are hard to scan. Most content earns its place for a multi-mode tool, but the structure could be much clearer.

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 a complex multi-mode tool with four parameters and no output schema, it covers the main modes, special category values, and the key return caveat that the answer is not returned. It still omits error behavior and the optional value parameter's role, so it is strong but not fully complete.

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 slug, play_id, value, and category. The description adds useful special-value semantics for category, but it largely repeats the schema's category examples and says nothing about the optional value parameter or slug, so the baseline 3 is appropriate.

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 opening states a specific verb and resource: it opens one clue on a Plot Speaks trivia board and returns its text, not the answer. That distinguishes it from game_answer, but the description never explicitly names sibling alternatives, and the multi-mode sprawl makes the core purpose slightly less crisp.

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 gives detailed mode-specific usage: category "final" when the board is clear, "next"/"skip"/"no steal" in survey or letter games, deck name in timeline games, and "rules"/"players" in Worms!/Yacht/Pigs!. It lacks explicit when-not-use guidance or named alternatives, so it is strong but not complete.

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