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

Annotations only cover the safety profile (read-only, idempotent, non-destructive, closed-world). The description goes well beyond: it warns the transcript is AI-generated synthetic speech that must be cited with moment and link and never as the author's words, explains fragment pagination via nextCursor, and names the withoutTranscript bucket plus four specific error codes.

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 usage trigger and information-dense throughout, with no filler sentences. It is a single long run-on paragraph, and the detailed return-field enumeration partially duplicates the output schema, which costs a point on tightness.

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 tool with an output schema and full annotation coverage, the description supplies everything else an agent needs: pagination loop, transcript provenance caveat, the no-transcript case, and the three not-found/unavailable error codes. Nothing required to invoke it correctly is missing.

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 100%, so slug, module, cursor and maxChars are already documented in the schema; the baseline of 3 applies. The description reinforces cursor semantics ('pass nextCursor back as cursor until it is null') but adds nothing for maxChars or the module identifier format.

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 precise verb+resource ('Returns the video lessons and podcasts of a course or of one module') and enumerates the returned fields, so it is immediately distinguishable from getModuleContent and getCourseModules. The opening 'Use when...' clause anchors the intent to a concrete learner need (a lesson, a podcast, or the exact moment something is said).

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 opening sentence gives a clear trigger condition and the body implies when to scope to a module vs. the whole course. However, it never names the sibling tools an agent might confuse this with (e.g. getModuleContent for text, getCourseModules for structure), so the routing guidance is contextual rather than explicit.

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