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

With no annotations provided, the description carries the transparency burden. It discloses the output (counts per age bucket) and optional state filter. However, it omits important behavioral details such as the underlying data scope (all businesses vs. private entities), the default behavior when no state is supplied, and any restrictions on state values beyond the schema's examples.

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, front-loaded with the purpose, and uses compact hyphenated ranges to list age buckets. Every word contributes essential information, making it highly concise and well-structured.

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 the tool's simplicity (one optional parameter, no output schema), the description covers the essential output structure (counts per age bucket) and the filter option. It misses a few contextual details, such as the population being measured and behavior without a state filter, preventing a perfect score. Overall, it is nearly complete.

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 single parameter 'state' has 100% schema description coverage, stating 'Filter by state: FL, NY'. The tool description only repeats this with 'Optionally filter by state,' adding no new semantics, default behavior, or formatting guidance. Per rubric, a baseline of 3 is appropriate when the schema fully documents parameters.

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 tool's purpose with a specific verb 'Get' and resource 'business age distribution', enumerating exact age buckets (0-4, 5-9, ..., 40+). This distinguishes it from sibling tools like private_stats and private_type_breakdown by specifying the aggregation type and granularity.

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 provides clear context for when to use the tool (to retrieve age distribution data) and mentions the optional state filter, implying the main use case. It does not explicitly exclude alternatives, but the focused scope makes its usage apparent. No explicit alternative tool references are given, so it stops short of a 5.

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