Initialize Shared Project Context

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

With no annotations provided, the description carries the behavioral disclosure burden. It transparently states that files are created, existing files are skipped, and the 'force' flag changes this behavior. This is sufficient for a file-initialization tool, though it could mention whether force overwrites rather than merges.

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, focused sentence that front-loads the primary action and integrates the key conditional behavior. No unnecessary words or filler.

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?

The tool is relatively simple with two parameters and no output schema. The description covers purpose, file behavior, and the force parameter, making it complete enough for an agent to invoke correctly. Minor gaps around cwd defaults do not significantly reduce completeness.

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 coverage is 0%, so the description must compensate for missing property descriptions. It effectively explains 'force' ('Existing files are skipped unless force=true') and implies 'cwd' as the project directory. However, it does not explain cwd's default value or whether it is required, leaving some ambiguity.

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 uses a specific verb ('Create') and names the exact resources ('AGENTS.md and CLAUDE.md') and location ('project cwd'). It clearly distinguishes this tool from siblings like companion_reset or companion_open, which serve different functions.

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 states why to use the tool ('so Codex and Claude Code share the same project instructions') and the condition for existing files, implying it is meant for project initialization. It does not explicitly name alternatives or when not to use it, but the context is clear.

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