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

Goes meaningfully beyond the annotations by disclosing that the call consumes SEO add-on credits and requires the SEO Intelligence add-on, which is real cost/auth context an agent cannot get from the schema. Annotations already cover the safety profile (destructive/openWorld/idempotent), so no further burden is required.

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 tight sentences with zero filler; the core output definition is front-loaded and the credit/add-on caveat follows as a distinct, useful clause.

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 the add-on/credit constraint is covered. However, with 0% schema coverage the description leaves limit, refresh, language, and location unexplained, which is a gap for a 6-parameter 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% across 6 parameters, and the description only implies the roles of your_domain vs competitor_domain. It says nothing about limit (default 100), refresh, or the surprising language default of 'tr', leaving most parameters undocumented.

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 resource and scope: keywords the competitor ranks for that you do not, sorted by search volume. This clearly differentiates it from sibling keyword tools like seo_keyword_research, keyword_opportunities, and seo_ranked_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?

Frames the use case explicitly ('the content/ad opportunities you're missing') and notes the add-on requirement and credit cost. It does not name an alternative sibling or state when not to use it, so it stops short of a 5.

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