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

Annotations already declare readOnlyHint=true and idempotentHint=true. The description adds valuable behavioral context that the tool does not consume quota, which is not captured in annotations and clarifies resource impact. This goes beyond the structured metadata.

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 extremely concise—two short sentences that are front-loaded with the primary action and include a clarifying exclusion. Every word earns its place with zero fluff.

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 simple read-only tool with a single optional parameter and no output schema, the description covers the core behavior well. However, the missing explanation of the 'account' parameter means the tool is not fully self-explanatory, and the agent may not know how to populate it correctly.

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 must compensate for the undocumented 'account' parameter. It does not mention the parameter at all, leaving its meaning and usage entirely unexplained. This is a significant gap given the low coverage.

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 shows the connected ChatGPT subscription (email and plan). The explicit mention that it does not generate images distinguishes it from sibling tool codex_image_generate, making its purpose unambiguous.

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 provides clear context by stating this tool does not generate images or consume quota, implying it should be used for checking subscription info rather than image generation. However, it does not explicitly name alternative tools or provide when-not-to-use conditions beyond the generation exclusion.

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