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

With no annotations, the description carries the full burden of behavioral disclosure. It clearly states what the tool returns (the four statistic types), which is the primary behavioral trait. It doesn't describe side effects or response format, but for a read-only summary tool this is largely sufficient. The description provides more than a bare statement of purpose.

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 a single sentence that front-loads the core action ('Get summary statistics') and then enumerates the specific statistics. There is no wasted wording, and every element adds value.

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 that there are no parameters and no output schema, the description provides enough information for an agent to understand what the tool does and what it will receive. It lists all the statistic categories, which is essentially the complete output content. It could mention the return format, but that's a minor gap for a no-argument summary 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?

The tool has zero parameters, so the baseline is 4. The description adds no parameter information, but none is needed. It correctly focuses on what the tool does rather than on parameters that don't exist.

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 uses a specific verb ('Get') and resource ('summary statistics for the directory') and lists exactly what statistics are included (tool count, department count, pricing distribution, free-tier fact count). It clearly distinguishes itself from siblings like search_ai_tools or list_departments by focusing on aggregate metrics rather than listing or searching.

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 implies its use case (obtaining an overview of the directory) but does not explicitly state when to choose it over alternatives or when not to use it. It doesn't mention that for individual tool details one should use get_ai_tool or for filtering search_ai_tools. The usage context is self-evident but not explicitly articulated.

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