Read Codex status

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds transparency by detailing the exact data returned (latest diff, streamed events, etc.) beyond the annotation flags. It does not mention potential large responses from includeTurns, but that is covered in the schema parameter description.

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 a single, well-structured sentence that front-loads the main action ('Read a thread snapshot') and then lists all data components in a logical sequence. No filler or redundant content.

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?

With no output schema, the description adequately enumerates the key return categories (thread snapshot, turn state, approvals, etc.). It does not cover edge cases or polling behavior, but given the read-only annotation and schema parameters, it provides sufficient context for an agent to understand the tool's purpose and outputs.

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 description does not elaborate on any parameters, but the input schema already provides descriptions for 3 of 4 parameters (threadId, includeTurns, afterSequence). The only undocumented parameter, maxEvents, is self-explanatory. The description's phrase 'recent streamed events' loosely implies event-related parameters but adds minimal value beyond the schema.

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 reads a thread snapshot, current turn state, pending approvals, latest agent message, latest diff, and recent streamed events. It uses a specific verb ('Read') and resource, and the enumerated components distinguish it from sibling tools like codex_read_thread or codex_list_approvals.

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 implicitly conveys this is for getting a composite status view, but it does not explicitly state when to use this tool versus alternatives such as codex_read_thread or codex_list_approvals. No exclusions or alternative recommendations are given.

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