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

With no annotations, the description carries the full burden. It does disclose one genuinely useful behavioral trait beyond structured fields: results vary by date, and puzzles from earlier days include their answer. It omits not-found/error behavior and any permission or rate-limit context, leaving meaningful gaps for a zero-annotation 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?

Two short sentences, front-loaded with the core action, and no redundant or filler wording. Every clause contributes information.

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 one-parameter read tool with no annotations and no output schema, the description covers what is needed to call it and flags the notable answer-inclusion behavior. It could be stronger by stating the not-found behavior and confirming it is a read-only lookup.

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 description coverage is 100%, and the schema already provides the id type, max length, required flag, and a concrete example value. The description adds no format or semantics beyond "by id", so the baseline 3 applies.

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?

"One puzzle by id" gives a specific retrieval verb and resource, and the singular framing implicitly separates it from the list-style sibling puzzles_today. It does not explicitly address puzzle_data, which sounds like it could also return a single puzzle's contents, so an agent cannot fully disambiguate the two from this text alone.

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 only implied: fetch a single puzzle when you already have its id. There is no explicit "use this instead of X" statement naming puzzles_today or puzzle_data, and no guidance about calling answer_submit afterward. The note about earlier-day answers hints at a workflow but never states one.

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