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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered without the description. The description adds genuinely useful behavior in the form of the 'newest first' ordering, the per-topic ready_undone aggregate, and the implicit filtering role of the parameters, but says nothing about pagination, empty results, or what 'active profile' means operationally.

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?

It is a single dense sentence with the scoping information ('active profile, newest first') front-loaded and no filler. The long parenthetical field dump is information-dense rather than padded, though it reads as a schema restatement in prose form.

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 correctly carries the return-shape burden and does enumerate the fields returned, which is the right instinct. But it omits how the two filters behave and gives no usage context against a large sibling set, leaving an agent unable to predict results for a filtered call.

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 0% for both parameters, so the description must compensate and it only partly does: it enumerates the status values (building, ready, failed + error), which is real added meaning for the 'status' filter. However, the 'topic' parameter's matching semantics (exact, prefix, case sensitivity) are never addressed, and neither filter's default-empty-string behavior is explained.

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 conveys that this surfaces the lesson pool of the active profile ordered newest first, but it never states a verb such as 'list' or 'return' — the title 'List lessons' carries that load, not the description. The field enumeration implies a listing, yet nothing distinguishes this from siblings like lesson_get, progress, plan, or topics.

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 guidance on when to call this versus lesson_get, lesson_progress, plan, or topics, and no mention of whether topic/status filters are optional or what happens when omitted (defaults are empty strings). Usage must be inferred entirely from the name and siblings.

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