nexus_get_speedtest_urls

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds useful context that this runs against the v2 GraphQL pool and returns a structured array of mirror metadata, complementing rather than contradicting the 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 compact, front-loads the core purpose, gives a practical usage tip, and ends with a precise return format. Every sentence contributes value without redundancy.

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?

For a zero-parameter read-only tool with a stated output shape and supporting annotations, this description fully covers what an agent needs to select and invoke it. The use case, return type, and field names are all specified.

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 has zero parameters, so the schema leaves nothing undocumented. The description correctly focuses on what the tool returns rather than parameter details, matching the baseline for a no-parameter tool.

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 a specific verb and resource: 'Get CDN speedtest URLs to diagnose download issues via v2 GraphQL.' It clearly distinguishes this tool from siblings like download or search tools by focusing on speedtesting mirrors.

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 gives concrete guidance: 'Handy when downloads feel slow: test latency/throughput against each mirror and compare.' It does not explicitly name alternatives or exclusions, but the use case is clear and the tool is unique among siblings.

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