partner_performance

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

readOnlyHint=true already tells the agent this is a safe read, so the description's only added obligation is behavioral detail — time range, aggregation window, whether all partners are returned or only active ones, ordering. None of that is present. The description is essentially a field list that adds almost nothing beyond the annotation.

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?

It is one short fragment with no filler, so nothing is wasted — but it is under-specified rather than concise. There is no leading verb clause to anchor the reader, so the single sentence carries no structure.

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 parameters, no output schema and a readOnly annotation, the tool is low-complexity, so the bar is modest and the description conveys what fields come back. Still, an agent cannot tell what scope of partners or what time window the figures cover, which matters for a reporting tool. Adequate but with a clear 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?

The tool takes zero parameters, so per the baseline rule this scores 4; there is nothing the description needed to disambiguate. The absence of parameters is consistent with the field-list description.

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 fragment names the resource and the metrics returned (clicks, referrals, revenue, commissions) at the per-partner grain, which does distinguish it from aggregates like roi_summary or program_overview. However it is a bare noun phrase with no verb — it never says 'returns' or 'retrieves' — so the agent must infer that this is a read/retrieval tool rather than a computed or mutating one.

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 when-to-use statement, no mention of alternatives among the many siblings (roi_summary, roi_trace, program_overview), and no indication of prerequisites or when this is the wrong choice. The agent only gets the implied guidance of a metric name.

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