describe_metric

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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint, so the safety profile is covered. The description adds what the explanation contains (formula, filter, format), which is useful context, but says nothing about auth requirements, error behavior for an unknown metric name, or output shape.

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?

A single, front-loaded sentence with zero filler; the verb and the returned content come first. Nothing is wasted and nothing needs reordering.

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?

For a simple read-only lookup with annotations covering safety and no output schema to explain, the description is nearly sufficient. The remaining gap is the meaning and expected format of the single required argument, which neither the schema nor the description supplies.

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?

One parameter with 0% schema description coverage, so the description carries the full burden and does not meet it. It never explains what 'name' means — display name vs. metric identifier vs. qualified path — which is exactly the ambiguity that causes failed calls here.

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?

States a specific verb (explain) plus the resource (metric) and enumerates what the explanation covers (formula, filter, format). It is distinguishable from list_metrics and query_metrics, but never names those siblings, so differentiation is left to inference.

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?

No when-to-use or when-not-to-use guidance. Nothing tells the agent to pick this over query_metrics when it wants a definition rather than data, or over list_metrics when it wants a catalog. Usage is only loosely implied by the word 'explain'.

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