What's Due

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds useful behavioral context: it spans all courses, includes multiple item types, and sorts soonest first. No contradictions with annotations, and the added scope/sort details are valuable.

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 exactly two sentences, both information-dense and free of filler. It immediately states what the tool does and then gives use-case examples. Every sentence earns its place.

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?

This is a simple listing tool with a single well-documented parameter and an output schema, so the description needn't explain return values. It covers purpose, scope, sorting, and primary use cases, making it complete for an agent to select and invoke correctly.

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 single parameter 'days' is fully described in the schema as 'Horizon in days to describe in the result', so baseline is 3. The description does not elaborate on the parameter beyond implying time horizon via 'what's due this week', but it doesn't need to since the schema covers it.

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 states 'List what is due for the user across all courses' with specific item types (assignments, quizzes, scheduled events) and sorting order. This distinguishes it from siblings like list_assignments and get_syllabus, making the tool's purpose unmistakable.

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 calls it 'the primary tool for deadline planning' and gives example queries ('what's due this week', 'what do I have coming up'), which clearly signals when to use it. However, it does not explicitly mention alternatives or when not to use it, leaving some room for ambiguity.

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