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

Annotations already declare readOnlyHint=true, and the description adds meaningful context: the score scale, return fields, and update frequency. It also discloses the Gold tier requirement for history in the schema, but the description itself adds the update cadence and output composition, going beyond annotations.

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: the first defines the metric and return fields, the second lists usage triggers and update frequency. Every sentence carries crucial information with no redundancy or filler.

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 no output schema, the description compensates by listing the returned fields (trend, confidence, alignment_label, signed divergence_z_score) and explaining the score scale. It lacks detailed definitions of 'trend' or 'confidence', but overall it is complete enough for an agent to understand the tool's value and invocation.

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 'days' is fully described in the schema, including its optional nature, range, and tier prerequisite, so the description does not need to repeat it. The description does not add parameter-level detail, but schema coverage is 100%, so the baseline of 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 states the tool returns a 0-100 gas perception-gap score with a specific formula and output fields. The verb 'Returns' plus the resource 'gas perception-gap score' makes the purpose unmistakable and distinguishes it from other tools in the catalog.

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 'Call when' conditions covering user intents like gas price versus consumer mood and political risk. It lacks exclusions or named alternatives, but the when-to-use guidance is clear and abundant.

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