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

With only destructiveHint=false in annotations, the description adds valuable behavioral context: it discloses the locked/teaser response for unpaid modules, the need to teach socratically, and the iteration pattern with section_index. It does not go into side effects or deeper details, but for a read-like teaching tool it provides enough transparency beyond the sparse annotation.

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?

The description is two sentences long, front-loaded with the primary purpose, and every clause adds value—the entitlement behavior, the pedagogical instruction, and the advancement pattern. There is no fluff or redundancy, making it an exemplar of concise, structured tool documentation.

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?

Given that an output schema exists and the tool is relatively simple, the description covers the core interaction flow (get section, handle lock, teach, advance). It does not enumerate all return fields, but the output schema covers that. The only minor gap is not specifying what happens at the end of a module or how to handle errors beyond locked/teaser, but overall it provides enough for correct invocation.

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 compensate. It partially does: 'section_index' is implied through '+1 to advance,' and 'module' is contextually referenced via 'Free module is open.' However, 'course' and 'auth_token' are left to name inference, and the exact range or format of section_index is not clarified. This is acceptable but not comprehensive.

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 clearly states the tool's function: 'Get one lesson section's content + the teaching protocol for it.' It uses a specific verb ('Get') and identifies a distinct resource ('one lesson section' plus its teaching protocol), differentiating it from siblings like get_lesson or get_outline. The mention of 'section_index' and advancement further clarifies its specific role.

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?

The description gives practical guidance: it explains that free modules are open but paid modules need an active entitlement, and it instructs to 'Teach it socratically, then call again with section_index+1 to advance.' This implies a sequential usage pattern and sets expectations for when to call. However, it does not explicitly contrast with sibling tools or state when not to use it, which would be clearer.

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