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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description does add genuinely non-annotation information: a usage-based cost estimate (~$0.04/request) and a warning that final settlement may differ, which is useful behavioral context for a paid API call. It still omits rate limits, result shape, and any pagination behavior.

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 text is short and has no filler sentences, and the pricing caveat is front-loaded. However, its brevity is achieved by omitting the core purpose rather than by tight editing, so conciseness here is partly a symptom of incompleteness.

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?

An output schema exists, so return values need not be explained, and annotations cover the safety profile. But for a two-parameter, cost-incurring API call, the complete absence of purpose and parameter documentation leaves the definition too thin for an agent to invoke confidently.

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% and the description supplies no parameter information at all. 'domain' is largely self-evident, but 'database' (e.g. which regional Semrush database) is entirely undefined in both the schema and the description, leaving a required parameter ambiguous.

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 contains only a pricing/billing boilerplate block and never states what the tool does. The agent must infer the purpose entirely from the name/title 'Domain Paid Keywords', and the description does nothing to distinguish this from sibling get_semrush_domain_organic_keywords.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives. An agent cannot tell from this text why it would pick paid keywords over organic keywords (get_semrush_domain_organic_keywords) or the domain overview.

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