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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds one piece of genuine context – '(snapshot read)', signaling that results are a point-in-time snapshot rather than live data – but says nothing about staleness, pagination, or scope of eligibility.

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?

A single short sentence with the scope and snapshot caveat front-loaded; nothing is padded. Slightly terse for the amount of information an agent might want, but no waste.

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 values need not be described, and annotations carry the safety profile. For a one-parameter read tool this is largely complete; only the semantics of 'eligible' (which permissions/criteria) are left implicit.

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 0% for the single required ad_account_id, so the description must compensate. 'On one ad account' confirms the parameter identifies a single account, but no format, ID-prefix, or example is given.

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+resource (list pages) with a clear scope (eligible for ad creation, on one ad account) plus a snapshot-read qualifier. It is distinguishable from assets_list_pages by the eligibility/ad-creation framing, though it never explicitly names a sibling.

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 phrase 'eligible for ad creation' implies when the tool applies, but there is no explicit when-to-use, when-not-to-use, or named alternative (e.g. assets_list_pages vs. this narrower ad-account-scoped listing). Guidance is implied rather than stated.

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