get_cost_usage_summary

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It describes a read operation ('Get') but doesn't mention permissions, rate limits, data freshness, or error conditions. For a tool with no annotations, this is insufficient to inform safe and effective usage.

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 well-structured with clear sections for Args and Returns, making it easy to parse. It's front-loaded with the core purpose and avoids unnecessary details. However, the 'Returns' section could be more concise by omitting obvious details like 'List of'.

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?

Given the tool's complexity (4 parameters, no output schema, no annotations), the description is moderately complete. It covers parameters well but lacks behavioral context and usage guidelines. Without an output schema, the Returns section is helpful but could detail the summary structure more.

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 description adds significant value beyond the input schema, which has 0% description coverage. It explains each parameter's purpose (e.g., 'OCID of the tenancy', 'Start time in ISO format'), specifies defaults ('defaults to DAILY'), and clarifies formats ('YYYY-MM-DD'). This compensates well for the schema's lack of descriptions.

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 tool's purpose: 'Get cost and usage summary for a tenancy.' It specifies the verb ('Get') and resource ('cost and usage summary'), making it easy to understand. However, it doesn't explicitly differentiate from sibling tools like 'get_cost_by_compartment' or 'get_cost_by_service', which prevents a perfect score.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools like 'get_cost_by_compartment' or 'get_cost_by_service', nor does it specify prerequisites or exclusions. This leaves the agent without context for tool selection.

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