GitHub MCP Server

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

With no annotations provided, the description carries the full burden of behavioral disclosure but offers none. It doesn't mention that this is a destructive/mutative operation, what permissions are required, whether it can fail due to merge conflicts or branch protection rules, what happens on success (e.g., branch deletion), or any rate limits. The single sentence provides no behavioral context beyond the basic action.

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 maximally concise with just two words that directly state the action. There's zero wasted language or unnecessary elaboration. While this conciseness comes at the cost of completeness, as a standalone attribute, it's perfectly structured.

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?

Given this is a complex, mutative operation with 6 parameters and no annotations, the description is severely incomplete. While an output schema exists (which helps with return values), the description fails to address critical behavioral aspects like permissions, failure conditions, side effects, or differentiation from sibling tools. For a tool that can permanently change repository state, this is inadequate.

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 schema already documents all 6 parameters thoroughly. The description adds no parameter semantics beyond what's in the schema - it doesn't explain relationships between parameters (e.g., how commit_title and commit_message interact) or provide usage examples. This meets the baseline for high schema coverage.

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 verb ('merge') and resource ('a pull request'), making the purpose immediately understandable. However, it doesn't differentiate this from sibling tools like 'update_pull_request' or 'create_pull_request', which would require more specificity about what distinguishes merging from other pull request operations.

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 absolutely no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., pull request must be in a mergeable state), when not to use it (e.g., if conflicts exist), or how it differs from related tools like 'update_pull_request' or 'create_pull_request' from the sibling list.

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