create_branch

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

Annotations already indicate this is a write operation (readOnlyHint=false) and not destructive. The description adds the behavioral detail that the new branch is based on another branch (default: default branch), which is useful context. It does not address behavior on duplicate branch names or permission requirements, but given annotation coverage, a moderate score is 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?

The description is two sentences with no fluff. It conveys the primary action, the source branch default, and a relevant alternative, all in minimal space.

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 create operation with 4 documented parameters, the description sufficiently covers the core behavior and usage context. Though there is no output schema, for a side-effect tool this is acceptable; the description plus annotations give enough information for most agents.

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% for all 4 parameters, so the schema already documents each field clearly. The description adds no additional parameter meaning beyond what's already in the schema; the default for from_branch is already described in the schema. Baseline 3 is appropriate.

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 the specific action ('Create a new branch') and the resource ('from another branch'), with a clear default source. It also differentiates from sibling tools by mentioning that push_files can implicitly do this, distinguishing create_branch as the explicit standalone operation.

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 gives context by specifying the default source branch and noting that push_files can also achieve this implicitly. However, it does not explicitly state when to prefer create_branch over push_files or when not to use it, so the guidance is present but not exhaustive.

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