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

readOnlyHint=true already tells the agent this is a safe read. Beyond that, the description usefully discloses the payload shape (score plus per-drawing answer and guess) and the important behavioral detail that no run identifier is taken — it always returns the most recent run. It does not say what happens when no run exists or whether results are stable over time.

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?

A single tight sentence with no filler, and the most decision-relevant fact ('latest practice run') is placed early. It is perhaps slightly too compressed for a tool whose return values matter, but nothing is wasted.

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?

With no output schema, the description carries the burden of explaining returns, and it does so only at a high level — score, answers, guesses — without format, structure, or error behavior. The parameter side is fully covered by the schema, so the remaining gap is the shape of the result itself.

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?

There is a single parameter with 100% schema description coverage, and the schema already explains that `key` comes from create_key. The description adds no further meaning about the key, so the baseline of 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?

The description names a specific resource and scope: the score of the *latest practice run*, broken down per drawing into the correct answer and the agent's guess. That is concrete enough to distinguish it from `guess` and `start_practice`. It stops short of 5 because it never explicitly contrasts itself with those siblings or states a verb for the retrieval itself.

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?

There is no when-to-use guidance, no prerequisite (e.g. 'call after start_practice and guess'), and no mention of alternatives such as `get_image`. The word 'latest' faintly implies a run must already exist, but the agent has to infer that entirely.

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