lesson_list

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

Discloses behavior beyond the annotations: automatic newest-first ordering, relevance ranking with a per-line score, and the emitted line format. However, annotations declare readOnlyHint=false and idempotentHint=false, while the description's framing ('listing') suggests a pure read — the description never addresses this tension or mentions any side effect, persistence, or cost.

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?

Front-loaded with the core statement, then the default-vs-query branch, then the output format. Every sentence carries information and none is redundant padding.

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?

An output schema exists, yet the description still documents the line format, and the mode-switching behavior is fully covered. The gaps are the undocumented `k` cap (an agent cannot tell how many lessons come back) and no clarification of what 'materialized' means or whether an empty result is normal.

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%, so the description must carry the load. It does a good job on `query` (semantics, example value, how it changes ordering and adds a score) but never mentions `k` at all — not its role as a result limit nor its default of 20 — leaving one of two parameters undocumented everywhere.

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+resource ('Compact listing of materialized lessons') and immediately explains the two ordering modes, so an agent knows this is a retrieval/index tool rather than a fetch-by-id tool. It does not explicitly differentiate itself from lesson_get or lesson_neighbors, which keeps it below a 5.

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 conditional guidance: omit `query` for a recency listing, pass `query` (e.g. the user's opening request) to get relevance-ranked results, with the rationale that 'the newest lessons are rarely the relevant ones.' No exclusion against sibling tools like lesson_get/lesson_neighbors, but the when-to-use signal for the two modes is unambiguous.

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