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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered by structured data. The description adds genuine value beyond that: it discloses that the tool runs a real download/ping measurement inside the interactive widget, warning the agent that this is an actual network action needing a UI context rather than a pure data lookup.

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?

Two sentences, front-loaded with the usage trigger followed by the mechanics and output. Every clause earns its place and there is no repetition of the tool name or title.

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 an output schema present, the description need not explain return values, yet it still sketches them briefly, and no parameters exist to document. The only meaningful gap is that it does not help the agent choose between this and near-neighbour tools such as measure_latency or grade_connection_quality.

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 takes zero parameters, so there is nothing for the description to disambiguate and the baseline is 4. The description correctly spends no space on parameter semantics.

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+resource ('measure their current internet speed') and names the concrete outputs (Mbps, ping, quality grade), so the agent knows exactly what the tool produces. It does not, however, distinguish itself from closely related siblings like measure_latency or grade_connection_quality, which overlap in subject matter.

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?

There is an explicit trigger condition ('Use when the user wants to measure their current internet speed'), which is a clear when-to-use statement. There are no exclusions or routing hints, though, and with 36 siblings including measure_latency and grade_connection_quality, the agent gets no guidance on which of these overlapping tools to prefer.

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