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

Annotations already mark the tool as readOnlyHint=true, so the agent knows it's a safe read operation. The description adds value by disclosing the important constraint about free tier usage ('Works without an API key, limited daily use per IP'), which is critical for the agent to manage expectations and avoid surprising limitations. No contradiction with annotations.

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 two sentences and 33 words—extremely concise with zero filler. Every sentence adds vital information: the first states what it does, the second states when to use it and an important behavioral note.

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?

Given there is no output schema, the description could help by hinting at what the response includes (e.g., a list of keywords with scores). It does not do this, leaving the agent to guess the return format. However, for a simple extraction tool with 100% schema coverage and a readOnlyHint, this is a minor gap.

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% and each parameter has a clear description in the schema (e.g., 'store' lists enum values, 'store_id' explains the format). However, the tool description itself adds no additional semantic nuance about the parameters—it does not clarify how 'max' relates to the output, or how 'country' affects keyword extraction.

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 clearly states the verb ('Extract'), the resource ('keywords from an app's title and description'), and the output ('ranked by relevance'). It distinguishes itself from siblings like sonar_app_keywords (which likely retrieves tracked keywords) by emphasizing this is about extracting target keywords from the app's metadata.

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 description explicitly states the use case ('understanding what an app... is optimizing for'), which implies competitive analysis. It does not mention specific alternatives from the sibling list (e.g., sonar_app_keywords, sonar_keyword_metrics) for when you should use a different tool instead.

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