git_submodule

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

The annotations provide minimal safety information (not read-only, not idempotent, not destructive), so the description adds valuable behavioral context. It explains that 'update fetches and inits all submodules,' describes the return output including the 'No submodules found.' case, and notes that 'add needs both url and path.' This goes beyond the annotations without contradicting them.

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 four sentences, front-loaded with the core purpose, and every sentence adds value: usage, return info, parameter constraints, and an explicit alternative. No wasted words.

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 tool with no output schema and minimal annotations, the description covers purpose, usage scenarios, return values, parameter requirements, and a key limitation. It thoroughly equips an agent to select and invoke the tool 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?

The input schema already includes descriptions for all four parameters (100% coverage), so baseline is 3. The description adds extra meaning by specifying that 'add needs both url and path' and that 'update fetches and inits all submodules,' which clarifies parameter relationships and operation behavior 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 manages submodules with specific operations: 'show status, add a new one, or update all of them.' It distinguishes itself from sibling tools like git_clone and git_status by focusing on submodule-specific actions and explicitly noting it does not clone the superproject.

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 when-to-use guidance: 'Use this when a repository embeds external repositories, to check whether embedded repos are in sync, or to add a new dependency as a submodule.' Also names an alternative: 'Does NOT clone the superproject — use git_clone for that.'

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