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

Annotations already establish that this is a read-only, non-destructive, open-world operation. The description adds some behavioral caveats beyond annotations, such as no pagination, missing values not being zero, and result retention in call history, but these read like generic boilerplate and are not clearly tied to this tool's actual 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 description is short but poorly structured and under-specified. Sentences like 'Prices and publication are unapproved' and 'Seven-day source-freshness rules apply only to dependent requests' do not earn their place because they are opaque and not integrated into an explanation of the tool.

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 tool with five parameters, one required input, no output schema, and no schema descriptions, the description is completely inadequate. It does not explain what data is returned, how category keywords are selected, or what the parameters mean, so an agent cannot reliably invoke it.

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 carries the full burden for five parameters including categoryIds, limit, market, language, and categoryMatch. It mentions none of them, does not explain that categoryIds is required, and adds no meaning about enums, limits, or matching behavior.

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 effectively restates the title 'Category Keywords' and adds only generic language about 'Nexscope database facts.' It never states a specific verb, resource, or relationship such as returning keywords associated with category IDs, so it does not clearly distinguish this tool from siblings like keyword_categories or category_domain_comparison.

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 guidance on when to use this tool versus alternatives, no prerequisites, and no exclusions. 'One fixed task; no pagination' is an operational note, not usage guidance that helps an agent choose this tool.

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