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

Annotations already declare readOnlyHint=true, and the description adds valuable context: the signal is 'weighted momentum vs. baseline,' monthly since 1968, and the history feature requires Gold tier. This goes beyond the annotation baseline without contradicting it.

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 compact and front-loaded with the core purpose, then gives use-case triggers and an update note. It is slightly dense in the first sentence but contains no extraneous content.

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 covers the returned fields and usage context, which is helpful since there is no output schema. It does not explain how to interpret the 0-100 scale or the structure of top_drivers, but for a simple data-retrieval tool, it is sufficiently 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 only parameter 'days' is fully described in the schema, including its optional nature, limits, and Gold tier requirement. The description adds nothing about the parameter, so the schema bears the full burden. Baseline 3 is appropriate.

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 identifies the tool's output: a 0-100 US labor-market cooling signal with specific components (score, percentile, trend, top_drivers). It uses a specific verb ('Returns') and resource ('labor-market cooling signal'), making its purpose distinct from generic economic indicators.

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 explicit when-to-use guidance: 'Call when the user asks about labor market cooling or turning points, rising claims or unemployment, falling quits or hires, layoffs, or recession risk, or when timing risk-off moves.' It lacks mention of alternatives or when-not-to-use, so it falls 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.