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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so safety is largely covered. The description adds real behavioral context beyond that: the partial-update semantics ('Only the fields sent change'), the permission requirement, and the currency constraint — all things an agent needs before calling.

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?

Three sentences, front-loaded with the resource and its fields, then the currency/scope constraint, then permission and partial-update notes. No filler, though it is dense and the field list is somewhat redundant with the schema.

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 four-parameter, all-optional mutation tool with no output schema and annotations covering safety, the description supplies the key extras: permission prerequisite, currency scope, and partial-update behavior. Return-value formatting isn't needed since no output schema exists; remaining gaps are minor.

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 description coverage is 100%, so the schema documents all four parameters and baseline is 3. The description glosses each field and adds the 'organization's own currency' scope, but the currency note largely duplicates the hourly_cost schema text, so the added meaning is marginal.

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 gives a specific verb+resource (set ROI settings) and enumerates the fields affected (hourly_cost, default minutes saved, fixed monthly fee, platform-cost subtraction), so an agent knows exactly what this configures. It doesn't name a sibling, but no sibling in the list overlaps with ROI configuration, so ambiguity risk is low.

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?

It states a permission prerequisite ('Needs Agent Performance manage permission') and the partial-update rule, which is useful invocation context, but it gives no explicit when-to-use/when-not guidance or routing against alternatives like set_goals or define_outcome_unit. Usage is implied rather than spelled out.

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