github_repos_merge_upstream

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

No annotations are provided, so the description must fully disclose behavioral traits. It only states the action ('sync') without detailing side effects, required permissions (e.g., write access to the fork), or whether it performs a merge commit or rebase. For a mutation tool, this is insufficiently transparent.

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 that is direct and free of extraneous words. It efficiently communicates the core purpose.

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 the tool's complexity (a mutation that syncs a fork with upstream), the description lacks information about return values, error conditions, and the exact nature of the sync operation. The body parameter is underdocumented, and no output schema exists to compensate. The description does not fully equip an agent to invoke the tool correctly without external knowledge.

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 has 100% description coverage, so the baseline is 3. However, the description adds no extra meaning beyond the schema descriptions. The 'body' parameter is described vaguely as 'Request body (JSON object)' without explaining expected properties or format, leaving the agent needing additional context.

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 'Sync a fork branch with the upstream repository' clearly identifies the tool's function: merging changes from the upstream repository into a fork branch. It uses specific verbs and distinguishes the tool from siblings like 'github_repos_merge' (which merges branches within the same repo) and 'github_pulls_merge' (which merges pull requests).

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 implies usage for keeping a fork up-to-date but does not explicitly state when to use it versus alternatives or when not to use it. No guidance on prerequisites (e.g., having a fork configured with upstream) or exclusion criteria is provided, relying solely on the tool name and one-line description.

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