get_keyword_performance

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states what data is returned, not how the tool behaves — no return format, no pagination, no handling of the 'days' window, no statement that this is a read-only operation (which annotations would otherwise confirm). For a data-retrieval tool with zero annotation coverage, this is a significant gap.

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 a single front-loaded clause with zero wasted words — 'Per-keyword performance incl. QualityScore.' delivers the core purpose immediately. It is genuinely concise, though it achieves this by sacrificing completeness, which keeps it from a 5.

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 tool is simple (one optional parameter, no output schema), so the job is not large, but the description is still incomplete: the 'days' parameter is entirely unexplained and no behavior outside the return value is described. An agent would know what data arrives but not how to scope or interpret the request. Incomplete even for a low-complexity 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 0%, so the description must compensate for the undocumented 'days' parameter. It does not — 'days' is mentioned nowhere in the description. The schema supplies only the name, type, and default, leaving the agent to guess what the time range controls and how it is interpreted.

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 — 'Per-keyword performance incl. QualityScore' — and the resource type (keyword) distinguishes it from sibling performance tools such as get_campaign_performance, get_ad_performance, and get_geo_performance. The 'incl. QualityScore' detail adds a concrete, specific element. It falls short of a 5 because it never explicitly names the siblings it is not.

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?

Provides no when-to-use guidance, no exclusions, and no pointer to alternatives. The sibling set contains closely related tools (get_keyword_forecasts, discover_keywords, get_campaign_performance) that an agent might confuse it with, but the description gives no context for choosing among them. The intended use case is only implied by the name.

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