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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so safety is covered. The description adds non-obvious behavioral context beyond that: result ordering ('earliest first'), that each item carries a known-lines-by-heart figure, and that grading is a separate mutation via record_quote_review. It does not discuss empty-result behavior or pagination beyond the limit, keeping it short of a 5.

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 plus a compact example, with the scoping and ordering facts front-loaded and the follow-up tool named last in workflow order. No sentence is filler.

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, single-optional-param tool with an output schema and full annotations, the description covers purpose, trigger, ordering, and the next step, so an agent can invoke it correctly. Minor omissions (what an empty due-list looks like, whether limit truncates silently) are low-risk given the output schema.

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?

With 100% schema description coverage and a single optional 'limit' param already documented as default 5 / max 20, the schema does the heavy lifting. The description's only addition is an illustrative call, {"limit": 5}, which adds marginal clarity but no new semantics; 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?

States a specific verb ('Lists') and a precisely scoped resource: saved quotes and memorized poem passages that are due for review today in spaced-repetition practice, ordered earliest first, with known-lines counts. The 'due for review today' qualifier cleanly separates it from list_saved_quotes, so an agent can route correctly without opening either schema.

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?

Gives explicit trigger conditions ('reader asks to be quizzed... what is due for review... how many lines they know by heart') and names the follow-up tool, record_quote_review, with the condition that selects it ('after the reader answers'). Both when-to-use and the alternative path are stated, not implied.

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