guard_content

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

With no annotations provided, the description carries the full transparency burden. It discloses the return format (JSON with decision, findings, pathViolation) and behavioral expectations for blocked writes. It includes an example of protected paths (.git/hooks), adding meaningful context beyond schema. It doesn't elaborate on 'warn' semantics but is otherwise 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 concise: three sentences covering purpose, return structure, and usage guidance. It is front-loaded with the primary action and resource, and every sentence earns its place with no redundancy or fluff.

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 a moderate-complexity tool with no output schema, the description is sufficiently complete. It explains what the tool does, what it returns (decision, findings, pathViolation), and how to act on the result ('On block, do not write'). It lacks full detail on 'warn' and 'allow' handling, but an agent can infer safe usage from the provided information.

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 already provides detailed descriptions for both parameters: content ('Full proposed content — the new file content, or the replacement string for an edit') and file_path ('Path of the file about to be written'). The tool description adds little parameter-specific meaning beyond the schema, so the baseline score of 3 applies.

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 tool's purpose: 'Check a proposed file write against the Umbra guard engine BEFORE writing.' The specific verb 'Check' and resource 'proposed file write' are precise. It differentiates from siblings (scan_repo, get_score) by focusing on pre-write validation.

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 explicit usage context with 'BEFORE writing' and a direct instruction: 'On block, do not write — fix the content and re-check.' This tells the agent when and how to use it, though it doesn't explicitly mention alternatives or when not to use it relative to sibling tools.

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