get_subscription

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

No annotations are provided, so the description carries the full behavioral burden. 'Read' implies a non-mutating operation, and the cost-estimation exclusion sets a boundary, but the description does not disclose permissions, safety profile, return format, or side effects. For a zero-parameter account getter, this is thin.

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 waste. The primary purpose is front-loaded, and the boundary condition follows immediately. Every clause is useful.

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?

The tool is simple, but the description does not explain what subscription or usage fields are returned, even though there is no output schema. It also leaves the relationship to get_usage_report, get_budget_status, and get_account_info ambiguous. The definition is minimally adequate for calling the tool but incomplete for confidently choosing it among siblings.

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 there is no parameter meaning for the description to add. The schema is empty and requires no explanation, making the baseline score of 4 appropriate.

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: 'Read the account subscription and documented usage fields.' It also explicitly excludes cost estimation, which distinguishes it from estimate_cost. However, it does not clearly differentiate the tool from nearby siblings like get_usage_report, get_budget_status, or get_account_info.

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 one explicit exclusion, 'This does not estimate generation cost,' helps route agents away from estimate_cost. But the description gives no positive guidance on when to use this instead of get_usage_report, get_budget_status, or get_account_info. Usage context is therefore only implied.

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