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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful context beyond that: the ten supported marketplaces and the metric set returned (search volume, trends, PPC bids, ranking difficulty), which matters since there is no output schema.

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 opening sentence is well front-loaded, but the trigger enumeration is heavily redundant, listing 'keyword discovery', 'related keywords', 'keyword suggestions', and 'keyword mining' multiple times each. Roughly half the text is duplicated phrasing that does not earn its place.

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?

With 12 parameters, no output schema, and annotations covering safety, the description does enough to convey what comes back and where it works. It does not explain how the many filter parameters (word count, organic product count, search volume bounds) interact or what defaults apply, leaving gaps for a fairly complex 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 100% across all 12 parameters, so the schema already documents marketplace codes, sort defaults, and the min/max filter pairs. The description adds nothing parameter-specific beyond restating marketplace coverage and the metric list, so the baseline 3 applies.

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 first sentence gives a specific verb and resource (expands a seed keyword into related keywords) plus the returned metrics and marketplace coverage, so the core action is unambiguous. It never distinguishes itself from close siblings such as nexscope_amazon_keyword_intelligence, nexscope_amazon_keyword_overview, or nexscope_seo_keyword_expand, which an agent would need in order to choose correctly.

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?

The trigger list and the 'even if the user does not explicitly mention Nexscope' clause give clear positive usage context. However, there is no when-not guidance and no named alternative among the many sibling keyword tools, and the trigger list repeats the same phrases (keyword discovery, related keywords, keyword suggestions) several times, which adds noise rather than routing signal.

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