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 earns credit by adding behavioral context beyond that: discovery does not confer permission and restricted qualifications stay unverified, which tells the agent how to interpret the returned status.

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, no filler, with the read-only scope stated first and the caveat second. It is tight, though 'base evidence' and 'discovery' are jargon that cost clarity without costing many words.

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 low-risk read-only tool with no output schema and only two parameters, this is minimally sufficient: the agent knows what it reads and that results carry caveats. However, what 'base evidence' actually returns and how the snapshot relates to eligibility remain unspecified, leaving a real gap for a discovery-style call.

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 only 50%: customer_id is documented in the schema, but connection_context (a strict mctx_v1_ pattern token) is undocumented. The description adds nothing about either parameter, so it fails to compensate for the coverage gap.

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 gives a concrete verb ('Read') and enumerates the resource it returns: account status, currency, timezone and 'base evidence'. That is clear enough for an agent to know what it fetches, but nothing distinguishes it from nearby siblings like google_ads_accounts_list, google_ads_accounts_pull or setup_get_status, and the connection to 'eligibility' in the tool name is never made explicit.

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?

There is no statement of when to call this versus the many accounts_* and setup_* siblings. The line about discovery not granting permission is a caveat about interpreting results, not guidance on tool selection. An agent must guess its place in the workflow.

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