today

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

With no annotations, the description carries the behavioral burden, and it does disclose a meaningful trait: returned items deliberately withhold answers and supply only question plus location scope, ordered by due date and recurrence. It does not say whether the tool mutates review state (a separate 'mark_reviewed' sibling exists) or what the response looks like.

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?

One dense sentence with the core purpose front-loaded, followed by the two content categories. The parenthetical instruction is operational and earns its place; nothing is padded.

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 read-only recommendation tool with no output schema and no annotations, the description conveys the conceptual shape of the result (due wrong items + targeted practice for top error causes) but leaves the response structure and the one parameter undocumented. Adequate but with clear gaps.

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?

The single 'limit' parameter has 0% schema description coverage, and the description never mentions it — an agent cannot tell whether it caps number of due items, error causes, or days. The schema's min/max gives bounds but no meaning.

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 vague name 'today' is rescued by the description: it returns what is most worth re-practicing today, drawn from spaced-repetition due items (1/3/7/14/30-day intervals) plus the error causes with the highest recurrence. That is a specific resource and selection rule. It does not, however, distinguish itself from siblings like 'weakness' or 'method', which sound related.

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 explicit when-to-use or when-not-to-use guidance, and no sibling is named as an alternative (e.g., versus 'weakness' or 'list_sets'). The parenthetical 'give only the question and location scope, not the answer' is presentation guidance for the consumer, not a condition for choosing this tool.

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