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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description still adds real value by disclosing the sort order (newest first) and that `before` moves backwards through the feed rather than forwards — behavior not derivable from the annotations.

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?

A single short sentence, front-loaded with the resource and ordering, with the pagination tip in parentheses. It wastes no words, though the terseness leaves it borderline thin for a paged read tool.

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?

For a 4-parameter read tool with no output schema, the agent still lacks the return shape (what fields a post carries), how to detect the end of the feed, and how scopeId pairs with scopeType. The described ordering and cursor partly compensate.

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 50%: scopeType carries an enum explanation and `before` only says "ISO date/time". The description usefully clarifies that `before` is a backward-pagination cursor, but says nothing about `limit` (max 50, default 20) or what form scopeId must take.

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 names the resource (posts in a community) and its ordering, which is enough to identify this as a fetch/list operation. It does not explicitly say whether it lists posts or does something else, and never contrasts with the similarly-named get_community_comments or list_my_communities siblings.

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?

"page back with `before`" is a call-sequencing hint, not a when-to-use rule. There is no statement of when to prefer this feed over list_my_communities or get_community_comments, and no mention of prerequisites such as needing a valid scopeId for the chosen scopeType.

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