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

Annotations already declare read-only/idempotent/non-destructive; the description adds substantial context beyond them: the promote_pages vs. personal-role distinction, the meaning of an empty ad_account_pages result, permission diagnostics (pages_show_list), and a live verification note. It also clarifies that a missing Page is not an access loss, which directly shapes agent behavior.

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?

The critical guidance is front-loaded, but the text is dense and repetitive — the 'empty list is not a connector fault / not an access problem' point is restated three times across separate paragraphs. It is long relative to a single-parameter list 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?

An output schema exists, so return-value explanation is unnecessary, and the description still covers the key edge cases (empty list, missing permission, ad-account assignment) an agent must handle. For this tool's complexity, nothing essential is missing.

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?

The single account_id parameter has 0% schema description coverage, so the description must compensate; it does, explaining exactly what passing account_id changes (returns ad_account_pages with assigned_to_ad_account per entry). It doesn't specify the ID format or where to fetch it, which keeps it short of a 5.

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 opening sentence gives a precise verb+resource ('Lists the Facebook Pages managed by the connected Meta user') plus the returned fields (id, name, category). It also explains its role in the ad-creation workflow, which distinguishes it from the many other meta listing 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?

Explicitly states when to pass account_id (ad-account-specific ad building), what the alternative path is when ad_account_pages is empty (pick from the flat pages list and pass page_id directly to create_meta_adset/create_meta_link_ad first), and an explicit when-NOT ('Do not send the user to Meta Business Settings on the strength of this empty list'). This is a model of when/when-not guidance.

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