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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, so the safety profile is fully covered. The description adds one genuinely useful behavioral fact beyond the annotations: the token_state reauth_required condition and its prerequisite (Page must be reconnected). That is real added context, though limited to a single data state.

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?

Three tight sentences, front-loaded with the action and scope, followed by a data-state caveat and a downstream pointer. Every sentence carries information; no filler or repetition.

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 read-only list tool with no output schema, the description covers purpose, a caveat about unreadable accounts, and the follow-up call. It omits pagination/volume behavior and return shape, but annotations and the mentioned fields partially offset this.

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?

There is one optional parameter (fields) and schema description coverage is 100%, so the schema already documents it fully. The description adds no syntax, default, or field-selection guidance for 'fields', matching the baseline for a fully-covered single-param 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 (List) and resource (Meta ad accounts) plus the scope constraint: only accounts readable through connected Facebook Pages. This clearly distinguishes it from list_facebook_marketing_pages, but it does not explicitly separate itself from its closest siblings sync_facebook_ad_accounts and update_facebook_ad_account.

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?

Provides a concrete next-step directive ('Use the id with get_facebook_campaign_insights'), giving the agent a clear downstream usage path. It stops short of stating when to call this versus sync_facebook_ad_accounts, so no explicit exclusion or alternative is named.

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