start_codex_account_link

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

With no annotations, the description carries the full behavioral burden. It discloses that the return is a one-time verification URL/code and asserts that tokens are never exposed to MCP, which is meaningful security context beyond the schema. It does not mention details like expiry, whether an existing link is replaced, or side effects of repeated calls.

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 short sentences with zero filler. The purpose is front-loaded and the return/security note is concise and valuable.

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 initiation tool, the description is complete: it states the action, account scope, outcome (returns verification URL/code), and the key security guarantee. The output schema covers the return structure, so no critical invocation guidance is missing.

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 and the schema trivially covers them all, so the baseline is 4. The description adds no parameter-specific detail, and none is needed.

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?

Description states a specific verb ('Start'), resource ('Codex device authentication'), and scope ('current Lightbulb account'). It clearly identifies this as the initiation action for the auth flow, which distinguishes it from sibling tools get_codex_account_link_status and cancel_codex_account_link.

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?

Usage context is implied: the tool starts the device authentication process. However, it gives no explicit when-to-use vs alternatives guidance, such as mentioning that get_codex_account_link_status should be used to check status or that cancel_codex_account_link aborts the flow. The differentiation relies on the name.

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