Get cost summary

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

Annotations already provide readOnlyHint: true, indicating safe read operation. Description adds that this is spend data (not engagement) and mentions optional reconciliation drift. No contradiction; adds behavioral context beyond annotations.

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 sentences with zero wasted words. Front-loaded with purpose, then provides contrast. Highly efficient.

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?

Tool has 4 optional parameters with enums and no output schema. Description covers purpose, scope, and contrast with sibling. Could optionally mention response format but not required for clarity.

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 100%, so parameters are already well-documented. Description adds semantic context by mentioning 'reconciliation drift' corresponding to the includeReconciliation parameter and clarifying the tool's scope.

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 uses a specific verb 'Query' and resource 'production infrastructure costs', listing included providers and optional reconciliation drift. It also distinguishes itself from get_job_metrics by clarifying it's spend data, not engagement.

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?

Explicitly states when to NOT use this tool ('for a published job's audience numbers use get_job_metrics') and provides the alternative. Clearly defines the context (cost data).

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