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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds modest context beyond those annotations by specifying that this is a snapshot of configured KPIs and listing the computed fields returned, but it reveals no further behavioral traits such as freshness or aggregation behavior.

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 19-word sentence that front-loads the verb and resource, then compresses the deliverable into four concrete data fields. Zero filler words; every element earns its place.

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 low-complexity, read-only tool with one fully described optional parameter, a rich annotation set, and an output schema, the description covers the essential payload (target, actual, delta, trend). The only gap is usage/alternative context, which is minor given how self-contained and unambiguous this tool is.

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%: the single optional 'period' parameter is fully documented in the schema with its enum values, their exact date windows, and the 'month' default when omitted. The description adds nothing about parameters, but with this coverage the baseline 3 is appropriate — the schema carries the burden.

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 ('Get'), an exact resource ('status of all configured North Star KPIs'), and enumerates the returned fields (target, actual, delta, trend direction). The 'current status' framing plus the field list makes it distinct from every sibling, none of which target North Star KPIs.

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 provides no when-to-use guidance, no exclusions, and no alternative tools. Unlike get_calls, it never names a sibling to prefer for other metric questions (e.g., get_anomalies, get_pnl_summary), so an agent must infer the appropriate context from the name alone.

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