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

Annotations already declare readOnlyHint=true and openWorldHint=true, so repeating "this tool is read-only coverage only" adds little. The useful addition is that lesson-taking is outside this server's scope, which prevents wrong tool attempts, but nothing is said about pagination, response shape, or volume.

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 the purpose front-loaded, followed by the scope caveat. The phrasing "read-only coverage only" is slightly redundant, but nothing is padded.

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?

A simple one-parameter list tool with an output schema, so return values need no explanation. Purpose, scope, and the read-only limitation are covered; only cross-course output grouping and pagination behavior are left implicit, which the output schema likely handles.

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?

Only one parameter (course_ids) and schema coverage is 100%, with the schema itself explaining "One or more course ids to list lessons for." The description adds no format, ordering, or multiplicity detail beyond that baseline.

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?

States a specific verb and resource ("List Lesson activities") with the scope "across one or more courses." It is distinguishable from siblings like list_assignments or list_quizzes by resource, though it never names a sibling explicitly.

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?

Explicitly sets a boundary: taking a lesson / answering pages is not supported, so the agent knows this is retrieval-only. It does not name an alternative tool or say when to prefer a different listing endpoint, but the exclusion is a real usage constraint.

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