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

Annotations already cover readOnly, idempotent, and non-destructive, yet the description adds genuinely new context: quota consumption ("one full-content preview for a caller unless existing access covers this subject") and cost ("3-8k tokens"). It also notes the accepted input tolerance, useful behavioral detail beyond the safety profile.

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?

Four tightly scoped sentences, front-loaded with the primary purpose and followed by input acceptance, usage context, and cost. No filler, though the quota and expense points could be merged into one sentence.

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 values need not be explained, and the description covers purpose, input tolerance, usage context, quota consumption, and token cost. Sufficient for an agent to call it correctly, leaving only sibling routing unaddressed.

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 the schema already documents subjectSlug, guideSlug, and the privacy-safe intent enum. The description restates the fuzzy-match acceptance for guideSlug but adds no format or syntax detail beyond what the schema provides, matching the baseline for high-coverage schemas.

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 and resource — returns the full text of one Fiveable AP study guide as Markdown. It clearly distinguishes a single full study-guide retrieval, though it doesn't contrast itself against nearby siblings like get_cheatsheet, get_guided_notes, or get_unit_overview.

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?

"Suitable when a student asks to learn or review a topic" gives an implied use case but names no alternatives and no when-not condition. A sibling set with get_cheatsheet, get_guided_notes, get_key_term, and get_unit_overview demands explicit routing guidance that is absent.

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