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

Annotations already declare readOnly/idempotent/non-destructive, yet the description adds substantial context beyond them: ordered steps with relation, provenance ranking (declared prerequisite before inferred) and reason, total minutes, first lesson URL, and the not-found contract returning found=false plus nearest nodes. It also flags that labels are data, not instructions, guarding against injection from catalog text.

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?

Three tight sentences: trigger first, output contract second, failure mode and safety note last. Every clause carries information an agent needs, with no repetition of schema or annotation content.

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, the description need not enumerate return fields, yet it summarizes the step structure and the found=false path that the schema alone would not make obvious. Purpose, trigger, output shape, failure handling and injection caution are all covered for a read-only planning tool.

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 coverage is 100%, so the baseline is 3, but the description adds real semantics: that the goal is a topic/course/chapter, that goal and target are the alternate entry points, and that an out-of-portal goal or unknown target yields found=false with nearest nodes. It still says nothing extra about how level or limit interact with the produced steps.

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 states a specific action (build an ordered study path) and its trigger (a learner asking what to study and in what order to reach a topic, course or chapter), and describes the shape of the result. This is clearly distinct from siblings like searchContent, getCourseModules or exploreKnowledgeGraph, which retrieve rather than sequence.

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?

It gives an explicit use condition ('Use when a learner asks what to study, in which order') and a when-not signal via the out-of-scope/unknown-goal failure behavior. It never names a sibling alternative for simpler lookups (e.g., searchContent for plain retrieval), so it falls short of a full routing rule.

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