Update Default Branch

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

Annotations indicate destructiveHint=false and readOnlyHint=false (write operation). The description adds no behavioral context beyond 'change'. It does not disclose side effects or if the operation is reversible. With no additional disclosure, the description offers little value over the annotations.

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 sentence, concise but too minimal. It could incorporate more useful detail without being verbose.

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, low annotation coverage, and incomplete parameter semantics, the description leaves the agent uncertain about required identification and return format. It is incomplete for a write operation.

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% (no parameter descriptions). The description does not explain what 'project_id' is or how to provide it. It only mentions 'default branch' generically, not the parameter format. The description fails to compensate for missing schema detail.

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 'Change a project's default branch to an existing branch' clearly states the action (change), the resource (project's default branch), and the condition (existing branch). It distinguishes this tool from siblings like create_branch or protect_branch.

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?

No guidance on when to use this tool vs alternatives (e.g., creating a branch first, or when to use protect_branch). No prerequisite information (e.g., branch must exist, user permissions).

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