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

The annotations already declare readOnlyHint=true, and the description's 'List' verb is consistent. It adds useful context about the plan names and monitoring limits, but it does not disclose other behaviors such as return format, auth requirements, or potential variations. This is adequate for a simple read-only list, but not rich.

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?

The description is a single, front-loaded sentence that immediately identifies the tool's purpose and enumerates the plan categories. No wasted words.

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 zero parameters, no output schema, and a simple read-only listing, the description provides all necessary context for an agent to select and invoke the tool. It names the plans and the included attribute (monitoring limits), making it complete for its simple scope.

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 has zero parameters, so the description carries no parameter burden. Baseline for 0 params is 4, and the description does not need to explain any parameter semantics.

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 clearly states the tool lists Merlonix subscription plans and pricing, and it enumerates the specific plan names (Starter, Team, Agency, Compliance) and mentions monitoring limits. This specificity distinguishes it from sibling listing tools like list_my_alerts and list_my_assets.

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 implies this tool is for retrieving plan/pricing information, but it does not explicitly state when to use it relative to alternatives or include exclusions. Since there are no other plan-related tools among siblings, the context is reasonably clear, but the lack of explicit guidance holds it back from a 4.

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