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

Annotations already declare readOnlyHint/destructiveHint=false, and the closing 'Read-only' is consistent with that. The description goes further with behavior the annotations cannot express: cursor-based pagination ('when the reply ends with a cursor, call again with the same arguments plus that cursor'), page-size limits, and the fact that each row's post_id feeds get_post_analytics and tag_published_post. It stops short of describing metric timing/freshness or how per-platform figures differ, which is why it is not a 5.

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 purpose and scope before alternatives and pagination mechanics, and nearly every sentence carries operational information. The long parenthetical listing every metric (profile viewers, members reached, saves, sends, follows, lift and clicks) is dense and slightly slows scanning, though it does inform the agent what comes back.

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 7-parameter read tool with no output schema, the description covers the scope, the shape of each row, the pagination contract, and downstream tool chaining — enough to invoke correctly. What is missing is return-volume guidance beyond page size and any note on metric freshness or empty-range behavior.

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 every parameter already carries its own documentation; this sets the baseline at 3. The description adds only marginal semantics — that `author` behaves as on list_top_posts and that cursor must be paired with identical arguments — but leaves the period/start_date override relationship and platform enum behavior to the schema.

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 plus scope: 'List EVERY published post in a date range, newest first, a page at a time.' It also enumerates the metric payload and explicitly separates itself from list_top_posts, so an agent can distinguish it from list_recent_posts, search_posts and list_top_posts without opening any schema.

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 a concrete when-to-use ('build a full history or export') and names the alternative for the contrasting case ('for the best or worst few, use list_top_posts'). It also pre-empts a likely misuse by stating ranges may exceed a year, removing the ambiguity that might push an agent toward period-based windows.

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