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

The phrase 'Values discarded' hints that the operation does not modify the input, but it does not explicitly state side-effect freedom, error behavior, or whether any external resources are accessed. The tool name suggests a memory-related function, but that is unexplored.

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 extremely concise and contains no fluff. It uses two short sentences, both of which add relevant information without redundancy.

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?

The description provides insufficient context: it does not identify the input parameter, specify the return format (presumably an integer count), or clarify how the tool behaves with invalid JSON. Given the large parameter list and lack of output schema, an agent would struggle to call this tool correctly.

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?

The schema descriptions are internally inconsistent with the stated purpose. For example, the 'json' parameter says 'validate' while the tool claims to 'count keys', and all parameters are described as 'discarded', implying they are ignored. No parameter is clearly designated as the JSON input, making the schema misleading.

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 states a clear action ('Count keys in a JSON object') but does not specify which parameter contains the JSON object, leaving the input ambiguous among the 9 parameters. The extra note 'Values discarded' adds context but does not resolve the mapping.

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 usage guidance is provided. The description does not indicate when to prefer this tool over siblings like 'validate-json' or 'search-query-len', nor does it mention any conditions or prerequisites.

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