azure_query_costs_by_resource

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

No annotations are provided, so the description carries the behavioral disclosure burden. It does add the credential requirement and indicates the output shape (top-N spend with percentage of total). However, it does not disclose read-only behavior, default time range handling, behavior on auth failure, or how results are ordered when ties occur.

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 two concise sentences with no filler, and the main action is front-loaded. However, given six undocumented parameters and no annotations, the brevity results in under-specification rather than efficient coverage, so it is not a perfect 5.

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?

With no annotations, no output schema, and six parameters, the description is markedly incomplete for safe invocation. It omits date/timeframe semantics, resourceGroup filtering, response_format options, and error behavior. The credential note is helpful, but an agent would need to inspect parameter names and enums to call this correctly.

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 description coverage is 0%, so the description must compensate, but it only clarifies the 'top-N' concept. It does not explain startDate, endDate, timeframe, resourceGroup, or response_format. Parameter names and enum defaults in the schema do some self-documenting work, but the description adds minimal semantic value beyond the topN parameter.

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 a specific verb and resource: 'Show top-N Azure resources by spend with % of total.' This conveys the tool's core function and differentiates it from the general azure_query_costs sibling by the 'by resource' and top-N scope, though it does not explicitly name any sibling.

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 only usage-related information is 'Requires Cost Management credentials,' which is a prerequisite rather than guidance on when to choose this tool over alternatives. There is no mention of when to use this instead of azure_query_costs, azure_get_cost_forecast, or other sibling tools.

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