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

Annotations only declare the mutation/safety profile; the description adds substantial context beyond them — keyword-country pairs count against a quota, oversized batches are rejected atomically in full ('rejected in full'), and rankings arrive asynchronously. These are exactly the operational traits an agent needs before invoking.

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?

Five sentences, action verb front-loaded, and every sentence carries a distinct fact (identity resolution, quota, atomicity, no-app behavior, async rankings). Dense 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?

With an output schema present, the description needn't explain return values, and it covers the remaining gaps an agent needs: quota limits, all-or-nothing batch rejection, defaults for store/country, and the async ranking caveat.

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 already 86%, so the schema carries most parameter meaning. The description still adds value by explaining the appId/storeProvider defaulting logic ('resolve from project metadata unless overridden') and the keywords × countries quota interaction, which the schema alone doesn't state.

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?

Opens with a specific verb+resource: 'Adds keyword tracking for the requested stores/countries.' This clearly distinguishes it from suggest_keywords, list_keywords, and remove_keywords by scope of operation, though it never names a sibling explicitly.

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 usable context for calling it: identity resolves from project metadata unless overridden, and projects without a linked app can still track terms. It stops short of stating when to prefer this over suggest_keywords or add_keyword_competitors, so no explicit alternative routing.

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