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

With read-only annotations already covering safety, the description adds substantial beyond-schema behavior: `current` is a blended, scheduled-job-refreshed number with `updatedAt`, `current: null` means no data, and pairing/status rules live in `howToRead`. This is exactly the kind of context annotations cannot express.

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 response shape and scoping constraint are front-loaded, and each clause carries information (metric list, time windows, null semantics, status values). It is dense with backticked field names but not padded.

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 describe the return payload, and it does: `current`, `roasCoverage`, `expectedToDate`, `status`, `updatedAt` and `howToRead`. For a single-optional-parameter read tool this is sufficient to call and interpret correctly.

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 coverage is 100% and the single `clientId` parameter is fully documented in the schema ('Only this client's goals'), so the description only echoes the per-client scoping. Baseline 3 applies when the schema carries parameter meaning.

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 states precisely what is returned: goals on the Monitoring page, one paid-ads target per client over month/quarter/year to date, plus current value, progress and status. That is specific enough to tell it apart from sibling readers like get_ai_visibility_metrics, which it explicitly excludes.

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 gives a clear inclusion rule ('Paid-ads metrics only') and routes AI-visibility metrics to get_ai_visibility_metrics. It does not mention the write-side sibling set_goal or contrast with reporting tools like get_report_data, so the alternative-routing is partial rather than complete.

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