What's Due

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so safety is covered. The description adds valuable behavioral context: aggregates across all courses, includes assignment/quiz/event types, sorts soonest first, and accepts a horizon parameter. No contradictions with annotations.

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?

Two sentences, front-loaded with the core action. The first sentence states what, scope, content, and sorting; the second lists common use-case phrases. No filler or redundant exposition.

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?

Given a single optional parameter fully described in the schema, safe-read annotations, and an output schema present, the description supplies sufficient context: purpose, scope, item types, ordering, and typical user intents. No critical gaps remain.

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% for the single 'days' parameter, so the schema carries the parameter documentation burden. The description does not add extra meaning beyond mentioning 'this week' as an example use case, which is consistent with the parameter but not necessary given full schema coverage.

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?

Description uses the specific verb 'List', identifies the resource as 'what is due' with scope 'across all courses', enumerates item types (assignments, quizzes, scheduled events), and states sorting order (soonest first). It distinguishes itself from siblings by positioning as 'the primary tool' for deadline planning.

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 description explicitly lists use-case queries ('what's due this week', 'what do I have coming up') and calls itself 'the primary tool', providing clear guidance on when to invoke it. It doesn't explicitly name alternatives or exclusions, but the primary-tool phrasing implies priority over siblings.

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