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

Annotations already cover safety (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description usefully adds two behaviors annotations cannot carry: omitting a chapter returns the chapter list instead of notes, and the response includes answer keys. The trailing "Cheap" hints at cost, a genuine extra signal.

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?

Three short sentences, front-loaded with the resource and scope before the conditional behavior and use case. "Cheap." is a fragment but earns its place as a cost hint; overall there is little waste.

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 an output schema present, return-value detail is not required. The description covers the subject constraint, the chapter-optional branch, and the intended use, leaving only the subjectSlug format undocumented — a minor gap for a two-parameter read tool.

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 coverage is only 50% (chapterSlug documented, subjectSlug not), so the description must compensate. It explains that chapterSlug is optional and that its absence switches to chapter-listing mode, and it constrains subjectSlug to AMSCO-capable subjects. That meaningfully extends the schema, though it does not give the subject-slug format the way the schema does for chapter.

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 names a specific verb+resource: fetching AMSCO textbook guided-notes prompts with answer keys for a chapter, and scopes it to subjects that have AMSCO notes (e.g. AP US History). It is distinguishable from generic siblings like get_study_guide and get_guide_reading_questions via the AMSCO framing, though it never names an alternative explicitly.

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?

"Use for guided notes handouts and reading checks" gives a use case, and the subject restriction (only subjects with AMSCO notes) narrows applicability. However, it does not say when to prefer this over the many adjacent content tools (get_guide_reading_questions, get_study_guide, get_cheatsheet), so the guidance remains implicit.

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