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

Annotations already declare readOnly, idempotent, open-world, non-destructive, so the safety profile is covered. The description adds substance beyond that: it discloses that the response carries per-state notice counts and freshness dates, and warns about a data-coverage pitfall that would otherwise mislead the agent. It does not discuss auth, rate limits, or response format details, keeping it at 4.

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?

Three sentences, front-loaded with what is returned before the example questions and the caveat. The quoted example questions are somewhat redundant with the first sentence but do aid discovery/retrieval matching. Otherwise there is no waste.

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 no parameters, no output schema, and annotations covering safety, the description must carry the return-value semantics and usage context itself, and it does: it enumerates the returned fields (states, per-state counts, newest date) and explains the coverage caveat. Nothing needed to call it correctly is missing.

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 takes zero parameters, which is the baseline-4 case by rule. No parameter meaning needs to be conveyed, and the description correctly spends no words on arguments.

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 precisely what the tool returns: which US states WARN coverage extends to, notice counts per state, and the newest notice date per state. That functionally separates it from warn_search, warn_recent, and warn_company, which operate on notices rather than coverage metadata. It stops just short of naming the siblings outright, so it lands at a strong 4 rather than 5.

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?

It gives an explicit trigger: read this before interpreting an empty WARN search result as proof no layoffs were filed. That is real when-to-use guidance tied to a concrete failure mode of the sibling warn_search. It does not state when not to use it or name alternatives directly, so it is a 4, not 5.

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