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

Annotations already declare destructiveHint=true and idempotentHint=true, so the safety profile is covered. The description adds real value beyond that by specifying exactly what is destroyed in each case: all data points for a normal series, only the definition for a derived one. It stops short of saying whether the deletion is permanent or how a missing series is handled.

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 tight sentence with the destructive action front-loaded and the two behavioral branches clearly separated by 'or'. Nothing extraneous.

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 one-parameter mutation tool whose annotations already carry the destructive/idempotent profile, the description covers both modes of deletion adequately. Minor gaps remain around permanence and behavior when the series does not exist.

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?

Only one parameter and schema coverage is 100%, so the baseline applies. The schema's own description is a bare 'name' and the description does not clarify the expected series identifier format (metric name, series key, derived name), so it neither compensates nor detracts.

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+resource ('Delete ... a series') and even splits the operation into two distinct outcomes: purging points vs. removing a derived series' definition. It does not explicitly distinguish itself from siblings like delete_annotations or delete_job, but the resource is unambiguous enough that confusion is unlikely.

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 'or' clause implies two use cases (raw series vs. derived series), which is useful selection guidance. However, it gives no when-not conditions, no prerequisites, and no warning that this is irreversible despite destructiveHint=true.

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