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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds genuinely non-obvious context beyond that: the call is FREE (no coin cost, which matters given sibling tools that likely consume coins) and it enumerates the guide's content scope. It stops short of describing the returned guide's shape, but that is a minor omission for a read-only informational tool.

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 purpose before the usage constraints and content summary, so the most important sentence comes first. It is slightly padded by four near-synonymous example phrasings and a redundant negative list, but the exclusions do guard against over-triggering.

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?

No output schema exists, and the description compensates by listing what the guide displays (coin costs, input sources, 8 learning types, study games). With annotations covering safety and the single optional param documented in schema, the only gap is that resuming onboarding via user_id is never mentioned.

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?

Only one optional parameter and schema description coverage is 100%, so the schema already documents user_id as an 'Optional user ID to resume existing onboarding.' The description says nothing about it and adds no meaning — the baseline 3 applies when the schema does all the work.

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 — 'Show QuizLink's interactive feature guide' — and immediately scopes it to user questions about QuizLink itself. No sibling tool serves this purpose, and the description makes that distinction explicit rather than relying on the name.

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 both positive triggers with concrete example phrasings ('what is QuizLink?', 'show me QuizLink features') and an explicit exclusion list covering general questions, math, and conversation. An agent can decide whether to call this tool without any inference.

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