op3_query_downloads

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

The description adds several non-obvious behaviors beyond the annotations: rows are ordered oldest first, there is no way to reverse ordering on this endpoint, the limit selects the earliest rows, and per-listener identifiers are removed from output. These are exactly the behavioral details an agent needs to interpret results correctly.

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 dense but every sentence earns its place: core purpose first, then routing guidance, then ordering/limit behavior, then privacy. It avoids repeating schema fields or annotation contents.

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?

The description covers the non-obvious decision-relevant context: when to prefer siblings, ordering limitations, limit behavior, and removal of listener identifiers. Since there is no output schema, the returned row fields are not enumerated, which is a small gap, but the description is otherwise sufficient for an agent to invoke and reason about the tool.

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 100%, so the baseline is 3. The description adds meaningful cross-parameter guidance: limit interacts with the oldest-first ordering, and start is the way to reach recent rows. This enriches the semantics of limit and start without restating the schema.

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 opens by stating the exact resource and result: raw download rows for a show with every filter OP3 offers. It also distinguishes this tool from the aggregating siblings by calling it the escape hatch for questions they do not cover, so an agent can tell it apart without opening schemas.

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?

The description explicitly names the preferred alternatives (op3_show_downloads, op3_audience_summary, op3_geography, op3_app_share) and explains why raw rows should be avoided when possible: they are slow to fetch and expensive to reason over. It also gives concrete query strategy: because rows return oldest first, narrow the window with start rather than raising limit to see recent activity.

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