skillNinja_addSource

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 mentions that the repository 'should contain SKILL.md files,' hinting at a requirement, but fails to describe key behaviors: whether this is a read-only or mutating operation (likely mutating based on 'Add'), what happens on success or error (e.g., confirmation message, indexing), any rate limits, authentication needs, or side effects. This leaves significant gaps for an agent to understand the tool's behavior.

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 concise and front-loaded, with the main purpose stated in the first sentence and a Japanese translation added as a second sentence. While the translation adds redundancy for multilingual support, it doesn't detract from clarity. The structure is efficient, with no wasted words, though it could be slightly more informative without losing brevity.

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 mutating operation with no annotations and no output schema), the description is incomplete. It lacks details on behavioral traits, error handling, return values, and how it interacts with siblings. For a tool that likely modifies system state (adding a source), more context is needed to guide an agent effectively, making it inadequate for the given context.

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, with 'repoUrl' clearly documented as a GitHub repository URL. The description adds minimal value beyond the schema by implying the repository must contain SKILL.md files, which relates to the parameter's purpose but doesn't provide additional syntax or format details. Since schema coverage is high, the baseline score of 3 is appropriate, as the description compensates slightly but not substantially.

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 action ('Add a new GitHub repository') and the resource ('as a skill source'), specifying that the repository should contain SKILL.md files. It distinguishes from siblings like 'skillNinja_list' or 'skillNinja_search' by focusing on addition rather than listing or searching. However, it doesn't explicitly differentiate from 'skillNinja_install' or 'skillNinja_updateIndex', which might have overlapping purposes, keeping it from a perfect score.

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 minimal guidance on when to use this tool, only implying it's for adding GitHub repositories with SKILL.md files. It lacks explicit instructions on when to choose this over alternatives like 'skillNinja_install' (which might install skills from sources) or 'skillNinja_updateIndex' (which might update existing sources), and does not mention prerequisites or exclusions, such as whether the repository must be public or accessible.

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