traffic_stats

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds genuinely useful behavioral context: the output is 'parallel labels and data arrays' and dates must be dd-mm-yyyy rather than ISO. This is a real addition beyond annotations, though it does not touch auth, rate limits or error behavior.

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 short sentences with no filler; the purpose is front-loaded before the parameter notes. The 'parallel labels and data arrays' phrasing is slightly cryptic, which costs a point.

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?

An output schema exists, so return values need not be described. With three parameters at 0% schema coverage, the description covers the date format and default but leaves the period enum values and start/end pairing rules to inference, which is a clear gap for an agent invoking the tool.

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 description coverage is 0%, so the description must carry the parameter burden. It documents the start/end format ('dd-mm-yyyy (not ISO)') and the default ('today'), but never names the allowed period values (today, hours24) or notes that start/end are the alternative to period. It compensates partially, not fully.

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 resource and scope: 'Traffic used over time, as parallel labels and data arrays.' An agent can tell this returns time-series bandwidth data. However, it does not distinguish this from siblings like account_status or top_domains, which may also touch usage figures, so it falls short of a 5.

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 only usage direction is parameter-shape guidance ('Pass period, or start and end... Defaults to today'). There is no statement of when this tool is the right choice versus alternatives, nor any when-not condition, so the guidance dimension is largely unaddressed.

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