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

The annotations already declare this a safe, idempotent, closed-world read, so the description is not burdened with safety disclosure. What it does add is genuinely useful: it defines the semantics of the returned figures, clarifying that credits_remaining is the total spendable amount while purchased_credits_remaining is the subset bought as packs. It does not mention the shape of the plan portion of the response.

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, both load-bearing, with the return-value distinction front-loaded immediately after the purpose statement. No filler, no restatement of the name or title.

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 with no output schema, the description covers the essentials and compensates by explaining the two key return fields. It falls short only on the plan data, which is named but never described, and on the unresolved ambiguity with the getCredits sibling.

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 the baseline is 4. The description correctly implies a workspace-scoped, argument-free call and introduces no parameter confusion.

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?

States a specific verb and resource: returns the workspace's plan and credit balance. However, the sibling list contains a tool named getCredits, and the description makes no attempt to distinguish this tool from that one, so an agent cannot resolve the overlap from the text alone.

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 explicit when-to-use guidance and no routing to alternatives. The most important missing guidance is the relationship to the sibling getCredits, which appears to cover adjacent ground; the description leaves the agent to guess which tool answers which billing question.

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