List Codex sessions

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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds meaningful behavior beyond annotations by stating sessions are 'read straight from disk,' clarifying the source and implying no remote calls or state changes. This is useful context for an agent deciding whether invocation is safe and appropriate.

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 compact sentences, with the core action and return fields front-loaded and the usage guidance in the second sentence. No filler words and no redundancy with the schema.

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 list tool with three optional and fully documented parametershol, the description covers what the tool returns composites and why to use it. No output schema exists, but the description names the key return fields, making the tool safely callable without needing more context.

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 100%, so the schema already documents all three parameters. The description adds little beyond the schema, except that the returned data includes fields like working directory, which maps to the cwd filter. Baseline 3 is appropriate since the schema carries the full parameter burden.

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 states a specific verb and resource: 'List recorded Codex sessions' and enumerates the returned fields (id, name, working directory, last update). It clearly differentiates itself from session-consuming tools like codex_resume and codex_fork by positioning itself as the way to discover a session_id.

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?

Provides explicit usage guidance: 'Use it to find a session_id for codex_resume or codex_fork.' This names the dependent siblings and the exact purpose, leaving no ambiguity about when to select this tool over alternatives.

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