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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context by stating that it returns capability and plan information for the signed-in user and should be called before spending credits, though it does not discuss authentication requirements or response format beyond the listed fields.

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 tightly written sentences with zero waste. The resource and returned fields are front-loaded, followed immediately by the key usage instruction.

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 parameterless read-only account lookup, the description is complete: it states what is returned, who it applies to, and when to call it. An agent has enough information to invoke it correctly without needing an output schema.

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 there are no parameter semantics to explain. The description instead lists the account fields returned, which adds meaning about the output even though no output schema exists.

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 identifies the resource as the signed-in user's Retiplex account and enumerates the key fields returned: credit balance, plan, video-generation capability, and maximum script length. This is specific enough to distinguish it from all sibling tools, which focus on projects, media, and video generation rather than account state.

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 gives explicit usage guidance: 'Call this first, and before anything that spends credits.' This tells the agent exactly when to use the tool and why, with a clear prerequisite relationship to credit-spending operations.

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