list_lessons

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

Annotations already cover the safety profile (readOnly, non-destructive, open-world), but the description adds a genuinely useful behavioral fact: how to interpret an empty result. It doesn't discuss caching behavior or pagination, which the refresh parameter implies exists, so it is not fully transparent.

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 short sentences with no filler, and the empty-result caveat is placed right after the purpose statement. The opening sentence is a noun fragment rather than a crisp verb phrase, which slightly weakens the front-loading.

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?

Because an output schema exists, return values need not be explained, and the description covers the key interpretive case (empty list). For a simple two-parameter read tool this is largely complete, though token/paging size for large Lessons sites goes unmentioned.

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%, so both the course identifier formats and the refresh cache-skip semantics are already documented in the schema. The description adds no parameter-level detail beyond that, making the baseline 3 correct.

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 identifies a specific resource — the pages of a course's Lessons tool — and distinguishes it from sibling list tools like list_course_resources by contrasting Lessons with Resources. The phrasing 'Pages in a course's Lessons tool' is slightly fragmentary rather than a clean verb+resource statement, which keeps it just below a 5.

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 real selection context: many UG courses keep material in Resources instead, and an empty result means the course doesn't use Lessons — an implicit route to list_course_resources. There is no explicit 'use this when...' or named alternative 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.