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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds genuine behavioral context beyond that: the clue text is included, the reference solution is opt-in, and some puzzles have several valid solutions — a useful caveat that affects downstream comparison/checking. It stops short of auth or rate-limit details.

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?

Two tight sentences with zero filler. The core result (the puzzle and its clue text) is front-loaded, followed by the solution-conditional caveat.

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?

An output schema exists, so return-value detail is unnecessary, and the description covers the non-obvious piece an agent needs — the optional solution and the existence of multiple valid solutions. It could add a note about the id source or sibling routing, but is largely complete for a two-param read.

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 and the schema already documents both parameters. The description nevertheless adds meaning: it explains that the solution is 'only included on request,' clarifying the conditional semantics of include_solution beyond its terse schema label.

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 states a specific verb and resource ('One puzzle') and clarifies it returns the clue text models were prompted with, which distinguishes it from the plural list_puzzles sibling. It does not, however, explicitly name any sibling or state the singular-by-id retrieval role to contrast with get_puzzle_results or get_model_puzzles.

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?

Usage is implied (fetch a single puzzle, pass an id from list_puzzles), and it notes the solution is only included on request, which guides use of include_solution. But there is no explicit when-to-use/when-not guidance and no named alternative for adjacent needs like results or model comparisons.

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