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

Annotations already declare readOnlyHint=true, idempotentHint=true, and openWorldHint=false, so safety and determinism are covered. The description adds that the output covers per-plan inclusions and the free-tier allowance, but says nothing about whether it is a static catalog versus live data, or anything about shape or freshness.

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 short and front-loads the use case, but the second sentence largely restates the first ("what each plan includes" appears twice), so one of the two sentences does not fully earn its place. Trimming to a single sentence with a scope note would be tighter.

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 zero-parameter, read-only reference tool with no output schema, the description tells the agent what content to expect (plan list, plan inclusions, free-tier allowance). Little else is needed to invoke it correctly, though a note that it is static plan reference rather than account state would fully close the 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 there is no parameter semantics to explain and the baseline of 4 applies. The description correctly avoids inventing any filtering or argument behavior.

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 uses a specific verb ("Show") and a specific resource (dVeracity plans, plan contents, free-tier allowance), so an agent can tell it returns a static catalog of plan information. It does not explicitly differentiate itself from siblings like billing_status or credits_balance, which cover account-specific status and balances, so it falls short of a 5.

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?

"Use this when you need to know what each dVeracity plan includes or what the free allowance covers" gives a real when-to-use condition. However, it offers no exclusions or routing guidance against the similar-sounding billing_status and credits_balance siblings, leaving the agent to infer that this is reference data rather than account state.

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