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

Annotations only say readOnlyHint=true, openWorldHint=false, destructiveHint=false; the description adds essential behavior beyond that: some channels return an empty list, rows contain only identifiers and statuses (no gate), itemId is what subsequent report tools expect, and ad_id is the integrationId from list_ads. This is rich, accurate context.

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 description is long, but it is dense and front-loaded with the core purpose, then the empty-list caveat, return shape, filtering/paging, and related tools. Every sentence carries useful information; the only minor issue is that it reads as a solid block without clear paragraph or bullet separation.

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 no output schema, the description compensates by explicitly listing the return shape, explaining the empty-list case, covering filtering and pagination, clarifying what data rows do and do not contain, and pointing to related tools for deeper item data. For an 8-parameter list tool in a sibling-heavy context, this is complete.

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 strong at 88%, with descriptions on most parameters. The description adds value by grouping filter parameters by purpose, explaining the relationship between ad_id and list_ads, and clarifying that project_id is optional for single-project customers but required otherwise — information the schema does not convey.

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: 'List the individual listing items of one ADS integration — the per-product rows'. It clearly distinguishes this tool from bulk channels and related tools like get_ad_report, and explains what kind of channel produces these rows.

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?

Explicitly says when not to use it (Google Shopping style bulk channels) and names the alternatives (ad_status / get_ad_report). It also gives practical usage guidance: filter with koongo_status, channel_status, listing_id or product_id to find failures, page with limit/offset, and use get_ad_item_report for full error reports.

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