open_pr

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

Annotations already indicate readOnlyHint=false and destructiveHint=false, but the description adds a critical behavioral requirement: obtaining user approval before proceeding. This goes beyond the schema/annotations and provides safety-relevant context. It doesn't describe other side effects (e.g., notifications, CI triggers), but the approval note is valuable.

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: the first states the core purpose, the second delivers a mandatory safety step. Every word earns its place, and the critical warning is front-loaded. No fluff or repetition.

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 creation tool with 7 parameters but 100% schema coverage, the description is reasonably complete. It lacks an explanation of return values or potential errors, but no output schema exists and the approval requirement is the most important behavioral context. The tool's scope is simple enough that this is adequate.

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 baseline is 3. The description's phrase 'from one branch into another' loosely maps to head and base, but it adds no new detail beyond what the schema already defines (e.g., defaults, types). There is no extra semantic depth for parameters.

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's function: 'Open a pull request from one branch into another.' This uses a specific verb ('open') and resource ('pull request'), and the branch-to-branch scope distinguishes it from sibling tools like get_pr, merge_pr, or list_prs.

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 provides a clear, explicit usage prerequisite: 'ALWAYS show the user the title and body and get their approval before calling.' This tells the agent when to pause and consult the user, which is essential for a mutation tool. However, it does not explicitly mention alternative tools or when not to use it, so it falls short of full 5.

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