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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so safety is covered. The description adds genuine behavioral value: 'a missing score is never zero', the observed-not-forecast framing, and that each result carries its source and last-confirmed timestamp — all information the annotations cannot convey.

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 core definition and ranking mechanic are front-loaded in the first sentence, and each subsequent sentence covers a distinct concern (disclaimer, missing-data rule, provenance, no-warning routing). It is slightly dense, but no sentence is redundant.

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 output schema, the description usefully lists what a result contains (score, label, band, source, last-confirmed time, links) and disclaims forecasting. The main omission is guidance on choosing between the place, state, and county parameters.

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?

Schema coverage is 100%, so each of place/state/county is already documented with examples. The description adds nothing about how the three alternate addressing modes interact (precedence of free-text place vs. state+county), leaving a real semantic gap, but the baseline for full coverage is 3.

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 names a specific verb-and-resource: fetches the QuakeIndex 0-100 activity score for a US state or county, including its label and normal band. That is clearly distinct from sibling tools like earthquake_details or latest_earthquakes, though it never names those siblings to make the contrast explicit.

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?

Usage is implied by the framing question 'is this normal for here?' and the explicit disclaimer that it is not a forecast or risk rating, which helps the agent avoid misusing it. However, there is no explicit statement of when to pick this over earthquakes_near or was_that_an_earthquake, and no exclusions or alternatives are named.

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