Azure Monitor metrics

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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint false. The description adds behavioral detail beyond those: the return shape (min/avg/max/latest per series plus downsampled series), the list mode, and dimension-splitting via filter. It does not mention response limits or pagination, but these are minor for a read-only metrics tool.

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 compact and information-dense: it states the resource, enumerates typical metrics, explains both call modes, describes the return shape, and gives a concrete example. Every sentence earns its place, and the most important facts are front-loaded.

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 100% parameter schema coverage, strong annotations, and no output schema, the description provides a good picture of behavior and returns. It explains list mode, aggregation shape, downsampling, and filtering. It could mention the output structure more explicitly, but the tool is simple enough that this is a minor gap.

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 the baseline is 3. The description adds meaningful parameter behavior: omitting metrics triggers a listing mode, and filter is used to split by dimension (e.g., 'Instance eq \'*\''). The inline example ties resourceId, metrics, and hours together, going beyond the schema's field-level definitions.

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 identifies the tool as reading platform metrics for any Azure resource and gives concrete examples (CPU, memory, HTTP 5xx, response time). It distinguishes this from sibling tools centered on logs, activity, or resource health by focusing specifically on platform metrics.

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 explains two usage modes: omit metrics to list available metrics, or provide metrics to retrieve aggregations and time series. It does not explicitly name alternatives or exclusions, but the purpose is specific enough that an agent can infer when metrics are the right data source.

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