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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds genuinely non-derivable behavior: newest-first ordering, the conditional existence of the pending queue (only when moderation is on), that denied comments persist in admin, and that a Cotlet API key with app access is required.

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?

Front-loaded with the resource and scope, then the ordering/status semantics, then the cross-references and auth note. Sentences are dense but each carries distinct information; nothing is redundant with the schema.

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?

All five parameters are already documented in the schema and no output schema exists, so the description's job is behavioral context, which it largely delivers: ordering, status semantics, cross-tool linkage, and auth. Minor gaps (pagination behavior) are handled by the schema's cursor/limit descriptions.

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 meaning to the enum values (pending = approval queue gated on moderation; denied = comments you denied) and frames course_id as scoping to one course. This is above what the schema's terse enum descriptions convey.

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?

Specific verb (lists) plus resource (lesson comments) and explicit scope (across your school or one course), with the returned fields named (author, lesson, status, unread flag). It also distinguishes itself from the write siblings teachable_moderate_comment and teachable_reply_to_comment, which it references by name.

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?

Gives concrete conditions for the status values ('pending returns the Pending Approval queue, which exists only when Comment moderation is on; denied returns comments you denied') and points to the tools that consume the returned comment_id. It doesn't state when to prefer this tool over a broader comment listing, but the contextual routing is strong.

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