get_usage_details

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It clearly indicates this is a read operation ('Get') and specifies the scope ('current billing cycle'), but doesn't mention authentication requirements, rate limits, error conditions, or whether the data is real-time versus cached. The description doesn't contradict any annotations since none exist.

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 a single, efficient sentence that packs substantial information about what the tool returns. Every element serves a purpose: the action, scope, and specific metrics. There's no wasted language or 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 parameterless read operation with no output schema, the description provides good coverage of what information will be returned. It specifies the exact metrics (GB used, data cap/limit, days remaining, percentage used) and temporal scope (current billing cycle). The main gap is lack of information about authentication requirements or data freshness, but overall it's reasonably complete for this type of 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?

The tool has zero parameters with 100% schema description coverage, so the schema already fully documents the parameter situation. The description appropriately focuses on what the tool returns rather than parameter information, which is correct for a parameterless tool. Baseline for zero parameters is 4.

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 clearly states the specific action ('Get detailed internet data usage') and resource ('for the current billing cycle'), with explicit details on what information is included (GB used, data cap/limit, days remaining, percentage used). It distinguishes itself from siblings like 'get_account_overview' by focusing specifically on data usage metrics rather than general account information.

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 implies usage context ('current billing cycle') but doesn't explicitly state when to use this tool versus alternatives like 'get_account_overview' or 'get_bill_history'. No guidance is provided about prerequisites, timing considerations, or when not to use this tool.

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