add_labels

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

With no annotations, the description carries the transparency burden. It clearly indicates an additive mutation ('add') and the target resource, but it does not disclose whether label names must already exist, whether duplicates are ignored, or what error conditions occur.

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?

A single sentence carries all the essential information with no filler, and the core action is front-loaded. Every word earns its place.

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?

The presence of an output schema covers return-value expectations, and the description covers the core operation. However, it lacks guidance on label-management behaviors such as whether labels are created automatically, which is a meaningful gap for a mutation tool with no annotations.

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 0%, so the description must compensate for all four parameters. It adds meaning for 'labels' (one or more) and clarifies issue_number applies to issues or pull requests, but owner and repo are left entirely to their self-evident names without 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 states a specific verb (add), a resource (labels), and a target (issue or pull request), making it immediately clear what the tool does and distinguishing it from sibling tools like post_comment or assign_issue. It also correctly implies that issue_number may refer to a pull request.

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 action is self-contained: if the goal is to attach labels to an issue or pull request, this is the obvious tool. No sibling tool handles labels, so there is no ambiguity, though the description does not explicitly state when not to use it.

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