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

Annotations already declare readOnly, idempotent, openWorld, and non-destructive, so the safety profile is covered. The description adds one genuinely useful behavioral fact beyond that: the catalog is limited to measures 'we hold priced cost rules for', so unpriced upgrades are excluded. It says nothing about result size, pagination, or whether the response is exhaustive, and the openWorldHint is not elaborated on.

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?

Two sentences, front-loaded with the resource definition and followed by the actionable next step. The phrasing 'we hold priced cost rules for' is slightly convoluted but carries real meaning about scope, so little is wasted.

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?

An output schema exists, so return-shape explanation is rightly omitted, and the tool is a simple two-filter lookup. Still, the missing country format and the unstated behavior when both optional filters are omitted are real gaps for a tool with zero schema descriptions.

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 0%, so the description carries the burden for both parameters, yet it only restates their names ('by country and segment'). It does not say what country format is expected (ISO code, name, or free text), nor whether omitting both filters returns the full catalog. The segment enum is documented only in the schema.

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 names the resource precisely: a catalog of priced 'hardening and efficiency measures' identified by upgrade ids, scoped 'by country and segment'. That is a specific verb-less list operation with a clear scope. It stops short of explicitly differentiating itself from siblings like estimate_plan, but the returned entity (upgrade ids with cost rules) is distinct enough to act on.

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 second sentence gives downstream guidance ('Use these ids in estimate_plan and find_incentives'), which implies this tool is the id-lookup step before estimation or incentive search. However, it never states when NOT to call it, whether it is a required prerequisite, or how it relates to other catalog-style siblings. Usage is inferable but not spelled out.

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