skills.diff

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

No annotations are provided, so the description bears full responsibility for behavioral disclosure. It reveals the key requirement and that only the local side is computed. However, it does not specify whether the diff is destructive (likely read-only), the output format, or error handling. A more transparent description would clarify these aspects.

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 with two sentences, no unnecessary words. The first sentence front-loads the core purpose, and the second adds a critical behavioral note about the API key. This structure is efficient and easy to parse.

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 lack of an output schema, the description should ideally explain what the diff output contains (e.g., text, structured result). It also does not mention whether the tool is read-only or modifies files. While the key requirement is noted, the overall completeness is moderate; a user might need additional context to fully understand the tool's behavior.

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 schema already defines both parameters ('path' and 'slug'). The description does not add any additional meaning beyond what the schema provides, maintaining the baseline score of 3.

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: diff a local skill file against its cloud counterpart by slug. It specifies the verb (diff), the resources (local file and cloud counterpart), and the method (by slug). This distinguishes it from sibling tools like cloud.pushSkill or cloud.pullSkill which perform sync 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 some usage guidance by noting that the local-side diff is computed here and the cloud half requires MODELBOUND_API_KEY. This informs the agent that a cloud diff depends on an external credential, helping decide whether this tool is sufficient. However, it does not explicitly state when to prefer this tool over siblings like skills.readLocal or skills.listLocal for comparison tasks.

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