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

Annotations already mark readOnlyHint=true, and the description adds useful behavioral context: data source (NASA NeoWs), weighting logic, output fields (score, trend, confidence, top_drivers), and update frequency ('Updates: daily'). No contradiction with 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 three sentences, front-loaded with the primary function in the first sentence. Usage guidance and update frequency are relevant and succinct. Every sentence earns its place with no fluff.

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 (read-only, one optional param, no output schema), the description covers purpose, usage, output fields, and data source. The history mode is described in the schema, so no gap. Missing interpretation of score/trend is beyond expectations.

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% for the only parameter (days), and the schema description fully explains its behavior and Gold tier requirement. The tool description itself does not add parameter details, but the baseline of 3 applies because the schema already covers it.

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 specifies a clear verb+resource+scope: 'Returns a 0-100 index of near-Earth asteroid activity over the next 7 days' and includes methodology (weighted by proximity, size, hazard flag). It clearly identifies this as a distinct index tool for NEO activity, differentiating it from other adw tools by topic.

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?

Provides explicit when-to-use context: 'Call when the user asks about asteroid flybys, close approaches, or hazardous objects near Earth, or when timing space-themed content or programming around peak activity.' It lacks explicit exclusions or alternative tool names, but the context is clear enough for an agent.

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