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

Annotations already establish read-only, idempotent, non-destructive semantics, so the description is not needed for the safety profile. It does add genuinely useful behavior beyond annotations: short ranges return raw points while longer ranges return five-minute rollups, and the response discloses which in `source`. It stops short of saying when the rollup boundary kicks in or how dense the buckets become.

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 tight sentences with no filler: the first defines the operation and its options, the second explains the resolution behavior. Front-loaded and appropriately sized for the tool's complexity.

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 output schema, it usefully mentions the `source` field in the response, covering the main return-value concern. For a 7-parameter tool with only 2 required, however, it leaves defaults for `agg` and `interval` and the interaction between `range` and `interval` unexplained.

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 57%, and the description largely restates the agg enum and label filtering that the schema already defines. Its one real addition is explaining that `range` changes data resolution (raw vs five-minute rollups), which gives that parameter meaning the schema lacks. The `interval`, default agg and environment parameters get no additional explanation.

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 states a specific operation: aggregating a single metric into time buckets, with the exact aggregation functions and label filtering named. It is clear what the tool returns, but it never distinguishes itself from the close sibling get_timeseries (or list_metrics), so an agent cannot tell which to pick from the text alone.

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?

There is no explicit when-to-use or when-not-to-use guidance, and no mention of the obvious alternatives get_timeseries, get_breakdown or list_metrics. Usage is only implied by the fact that it works on 'one metric', which an agent could also infer from the name.

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