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

Annotations cover the safety profile (readOnly, idempotent, non-destructive), and the description adds traits the annotations cannot express: data freshness ('as of the app's last nightly sync') and aggregation granularity ('one row per issue code', account-level issues included). The staleness caveat materially changes how an agent should qualify its answer.

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 scoping constraint and the first-call instruction. The middle sentence enumerates return fields (severity, counts, sample products, destinations) that the output schema already carries, which is mildly redundant, but it supports the routing decision.

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 no explanation, and the description still supplies the sync-freshness caveat, the account-level coverage, and a complete follow-up workflow. Nothing an agent needs to call and act on this tool is missing.

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?

The tool takes zero parameters, so there is nothing to disambiguate and the baseline is 4. The description correctly implies whole-account scope rather than suggesting unimplemented filters.

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 and resource ('Google Merchant Center issues for this store') plus exact output granularity ('one row per issue code with severity, affected product counts, sample products and destinations'). It also scopes coverage explicitly (account-level issues, file feeds and native channel), which distinguishes it from list_products, list_feeds, and get_feed.

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?

Gives an explicit entry condition ('Call this FIRST when the merchant asks why products are disapproved or wants to fix issues') and names the downstream alternatives with sequencing: preview_product to inspect, set_product_override or update_feed_settings to fix. An agent knows both when to pick this tool and what to do next.

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