guard

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

With no annotations provided, the description fully bears the transparency burden. It discloses key behavioral aspects: determinism, no model/API key/token cost, the combined detection run, and the return value (safe_to_ship + block_reasons). It doesn't cover edge-case error behavior, but for a pure detection gate this is sufficiently 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 a single, well-structured paragraph that front-loads the core purpose, then explains the detection types, determinism, and use cases. Every sentence adds value 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?

For a tool with 3 parameters, no output schema, and no annotations, the description provides complete context: what it does, what checks it runs, how it behaves (deterministic, no cost), what it returns, and when to use it. It is sufficient for an agent to select and invoke the tool correctly.

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%, so the baseline is 3. The description adds no additional parameter information beyond what the schema already provides (e.g., it does not explain block_at or context in its own words). Thus it does not elevate the score.

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 identifies the tool as a deterministic pre-ship trust gate for AI/agent output, listing specific detection types (leaked secrets, prompt injection, PII/compliance). It distinguishes itself from the sibling guard_selftest by being the actual gate, not a self-test utility.

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 explicitly states when to use the tool: before sending model output to a user, committing generated code, or forwarding untrusted text into another prompt. It provides clear usage context but does not mention exclusions or alternatives, so it falls short of the top score.

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