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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, so the safety profile is covered. The phrase "Counts as browsing" hints at a cost/quota or activity-visibility side effect, but it is never explained, and pagination behavior (cursor-based, page-size limits) is left to the schema.

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 subject front-loaded and no wasted clauses. The second sentence is terse to the point of being cryptic, but it does not pad the definition.

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?

Five parameters, three required, cursor pagination, and no output schema: the description never says what each returned record contains (user ids, usernames, timestamps) or how paging terminates. For a paginated list tool with no output schema, that is a meaningful omission.

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 80%, so account_id, post_id, comment_id, limit and cursor are already documented, including cross-references to list_own_posts/list_user_posts and list_comments. The description adds no additional meaning about the parameters.

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 people who liked a comment" names a concrete resource and relation (comment reactions), which is enough to separate it from list_post_reactions and list_message_reactions by target object. It stops short of an explicit verb framing such as "list," but the intent is unambiguous.

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?

There is no statement of when to pick this over list_post_reactions or list_message_reactions, and no prerequisite guidance beyond the required ids being inferable from the schema. The only usage-adjacent text, "Counts as browsing," does not tell an agent anything actionable about selection.

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