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

Annotations already declare read-only, idempotent, non-destructive, and closed-world behavior. The description adds the [read] marker, explains the mode switch, and describes the returned identity fields, though it omits pagination or rate-limit 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 description is front-loaded and compact, with no filler. The nested parenthetical clauses make it slightly dense, but every sentence contributes relevant purpose, parameter, or return-value information.

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?

No output schema exists, so the description must explain return values; it does so by naming post_key, media key, and the creative object shapes for Meta and Instagram. It is sufficient for invocation but leaves pagination, ordering, and response envelope details unspecified.

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?

With 0% schema description coverage, the description carries the burden and explains all four parameters: page_key comes from the account's pages, ads_account_id or ads_account_uuid identifies the ad account, and instagram toggles linked Instagram posts. It does not clarify whether ads_account_id and ads_account_uuid are mutually exclusive or optional beyond 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?

The description clearly states that this tool retrieves a Meta page's recent posts, with a distinct Instagram mode. It identifies the resource and the key output fields used for ad creatives, though it does not explicitly name sibling alternatives like list_social_posts.

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?

It explains the two operating modes: Meta page posts by default, or linked Instagram posts with instagram=true. It also frames the use case around obtaining post_key or media key for creative construction, but it does not include explicit when-not-to-use guidance or alternative tool names.

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