get_focus_costs

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

With no annotations provided, the description carries the full burden. It explains the return format and effect of grouping, and implies it's a read operation (data retrieval). However, it does not explicitly state that it is non-destructive or mention authentication/rate limits. Given no annotations, a score of 3 is appropriate as it provides reasonable but not exhaustive behavioral context.

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 a clear one-line summary followed by parameter details and return format. It is front-loaded with the main purpose. The explanation of the FOCUS standard adds useful context but is slightly verbose. Overall, it is concise and efficient for a tool with 4 parameters and no output schema.

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 no output schema, the description covers all necessary aspects: default values, parameter constraints, and return fields (BilledCost, EffectiveCost, etc.). It explains grouping behavior and the normalization standard. There are no gaps in understanding what the tool does, what inputs are accepted, and what outputs are produced.

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 coverage is 0%, so the description must compensate. It provides detailed descriptions for each parameter: start_date and end_date as ISO date strings with defaults, provider as optional filter with explicit enum values (aws, azure, gcp), and group_by with possible values and effect. This adds significant meaning beyond the schema's type-only information.

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: returning unified cost data in FOCUS 2.0 format across all connected cloud providers. It specifies the verb (return), resource (unified cost data in FOCUS 2.0 format), and scope (across all connected cloud providers). This distinguishes it from sibling tools that are provider-specific or use different formats.

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 context for using the tool (e.g., optional filters for date range, provider, grouping) but does not explicitly state when to use this tool vs alternatives like get_costs_by_service or get_cost_summary. It implies its usage for normalized multi-provider cost data but lacks explicit when-not or alternative guidance.

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