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

Adds a critical behavioral caveat that impressions are AD impressions, not search volume, and clarifies that rows carry ad_type SP/SB with SD targets handled elsewhere. Annotations already declare readOnlyHint=true and destructiveHint=false, so the description adds meaningful context without contradicting them.

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 sentences, each earning its place: purpose and scope, return fields, then a key caveat and alternative. Front-loaded and free of filler.

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?

Covers output fields, the SP/SB scope, and the impressions caveat well, but with 21 parameters and no output schema, the lack of date-range and filtering semantics for start_date/end_date/period_days leaves an agent with gaps when constructing queries. Useful for the core case but not fully complete for the parameter space.

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 description mentions 'metric threshold filters,' which maps to acos_max, spend_min, and clicks_min, but many parameters (start_date, end_date, period_days, campaign_id, keyword_contains, campaign_name_contains) are left unexplained in both schema and description. With 71% schema coverage, the description only partially compensates for the undocumented parameters.

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 uses a specific verb ('Query') and a precise resource ('keyword/target bid performance') across Sponsor Products and Sponsored Brands, distinguishing SD targeting (ppc_query dataset sd_targets) and organic search volume (brand_sqp). It clearly differentiates this tool from nearest siblings.

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 routes users to ppc_query for SD targeting expressions and to brand_sqp for organic search-query volume, giving clear alternatives for related but distinct needs. It does not state general when-to-use versus other PPC tools like ppc_campaigns or ppc_ad_groups, but the purpose is clear enough.

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