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

Despite annotations only saying destructiveHint=false, the description adds meaningful behavioral details: the question is 'deterministic per day' and 'drawn from modules they've started,' and calling with done=true 'logs it and bumps the streak.' This discloses a state-changing side effect beyond the annotation. It lacks details on auth/errors but covers the core behavior well.

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 compact and front-loaded with the concept 'The two-minute drill.' It packs essential instructions into one sentence, though the run-on structure with semicolons could be clearer. Every clause carries information, so it earns a 4.

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?

The two-phase interaction is well explained, and an output schema exists, so return values need no description. However, the required 'course' parameter is completely undocumented, which is a significant gap. The tool's simplicity and output schema save it from a lower score, but it's only minimally complete.

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?

The description explicitly explains the 'done' parameter ('call again with done=true to log it') but provides no meaning for the required 'course' parameter or 'auth_token.' With schema description coverage at 0%, the description was expected to compensate but does not, leaving critical parameter semantics undefined.

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 identifies the tool's purpose: 'today's spaced-recall question + the learner's day streak' with explicit actions 'Call it to fetch today's question' and 'call again with done=true to log it and bump the streak.' This distinguishes it from sibling tools like recall_questions by emphasizing the daily drill and streak mechanics.

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?

Provides clear step-by-step usage: first call to fetch, then after revealing the answer, call again with done=true. The 'daily habit' framing implies the intended use case. However, it does not explicitly contrast with alternatives or state when not to use the tool, so it falls short of a 5.

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