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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the scoping constraint (portfolios the connected account administers), which is genuinely useful, but says nothing about pagination, result ordering, permission requirements, or what happens when the account administers none.

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 sentences, zero filler, with the scope and the downstream dependency front-loaded. Nothing in it is redundant with the title or annotations.

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 has some burden to signal what comes back; 'List the Business portfolios' plus the ad-account constraint conveys the shape and the reason to call it. Only minor gaps remain, such as whether results are paginated or how to handle an empty list.

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% and both parameters document their own fallback rules (accountId from list_accounts vs profileId from list_profiles, and the requirement that they agree). The description adds no parameter-level information beyond that, so baseline 3 applies.

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 (list) and resource (Business portfolios) with a scoping qualifier: only those the connected Facebook account administers. It differentiates from the ad-account family by naming ads_create_account as the dependent consumer, though it never contrasts with the more closely related ads_list_accounts.

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?

The second sentence implies a workflow: run this before ads_create_account, since ad accounts must live in one of these portfolios. That is useful implied context, but there is no explicit when-to-use statement and no guidance on how this relates to ads_list_accounts or get_tree, which an agent would plausibly confuse it with.

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