Run an MCQL report query

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

Annotations already mark the operation as read-only and idempotent, and the description adds valuable behavioral details beyond that: field naming differences, the no-SELECT* rule, required date ranges, opt-in requirements, and the fact that each result row has exactly one populated view object. No contradictions with annotations.

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 well organized: it opens with the core function, lists relevant tables, provides query rules, and closes with the product-filtering use case. The list of view names is long but necessary, and every sentence contributes useful information; only slightly less scannable due to the packed table list.

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?

For a query tool with no output schema, the description covers the critical context: supported tables, query rules, example syntax, prerequisites, result-row behavior, and the key sibling alternative. Pagination is already documented in the parameter schema, so nothing essential is missing for an agent to call this tool 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%, so the schema already documents all four parameters. The description goes beyond the schema by clarifying query-level semantics such as snake_case versus camelCase, valid table names, the no-SELECT* restriction, and the date-range requirement for performance views, adding meaningful guidance for the query parameter especially.

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 a specific verb and resource ('Runs a Merchant Center Query Language (MCQL) query via reports:search') and enumerates the exact supported tables. It also differentiates this tool from sibling list_products by noting it is the way to filter products, making its purpose unmistakable.

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 provides concrete usage conditions: performance views require a date range, price_* views require the Market Insights opt-in, and product filtering should use this tool because list_products has no filter. This gives the agent explicit when-to-use and when-not-to-use guidance relative to alternatives.

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