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

Annotations only declare readOnlyHint=false and openWorldHint=true; the description adds nothing about cost, quotas, data scope, or result shape. With zero annotation coverage of what actually happens on a call, the description carries the full burden and delivers nothing.

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?

It is one short clause with no padding, but this is under-specification rather than conciseness — the single sentence conveys no actionable information beyond the title.

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?

A 12-parameter keyword-research tool with no output schema and no annotations describing behavior needs a real description. Nothing here explains what a call yields or how the many filters interact, leaving the agent to guess from the schema alone.

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 100% across all 12 parameters (marketplace enum values, sort default, volume/word-count/ranking filters), so the schema already does the work. The description adds no extra meaning, which is the baseline case.

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 restates the tool name and title almost verbatim ("keywords/by keyword API") without saying what the tool actually returns — keyword ideas, search volumes, rankings? There is no verb describing the operation, only a resource path fragment.

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?

No indication of when to use this versus the many adjacent siblings, notably nexscope_data_js_keywords_by_asin (ASIN-seeded) or nexscope_amazon_keyword_expansion. The 'by keyword' phrasing is the only hint and the agent must infer the distinction.

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