GitHub MCP Server

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the action without detailing traits like pagination behavior (implied by parameters but not described), rate limits, authentication needs, or error handling. For a read operation with multiple parameters, this leaves significant gaps in understanding how the tool behaves beyond basic listing.

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, straightforward sentence: 'List labels in a repository.' It is front-loaded with the core action and avoids unnecessary words. Every part of the sentence serves a purpose, making it highly concise and well-structured for quick comprehension.

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 simplicity (a read operation with clear parameters and an output schema), the description is minimally adequate. However, it lacks context about what 'labels' are, how they relate to other tools, or any behavioral details. With no annotations and an output schema, the description should ideally provide more guidance but meets the basic requirement for a list tool.

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%, with clear descriptions for all parameters (owner, repo, per_page, page). The description does not add any meaning beyond the schema, such as explaining parameter interactions or constraints. However, since the schema is comprehensive, a baseline score of 3 is appropriate, as the description does not detract from but also does not enhance parameter understanding.

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 tool 'List labels in a repository,' which clearly indicates a read operation on labels. However, it lacks specificity about what 'labels' refers to (e.g., GitHub issue labels) and does not differentiate from sibling tools like 'list_issues' or 'list_tags,' which might list related but different resources. This makes the purpose somewhat vague but not misleading.

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 no guidance on when to use this tool versus alternatives. It does not mention any context, prerequisites, or exclusions, such as comparing it to 'list_issues' for issue-related labels or 'create_label' for adding new ones. Without such information, users must infer usage from the tool name alone.

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