sentinel_diff

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

With no annotations provided, the description carries the full burden and does so excellently. It discloses the output behavior (ranked alerts, likely cause, proposed fix), the meaning of status=fail, and the pure/headless nature (two snapshot files). This fully informs the agent of the tool's operational impact and safety profile.

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 moderately long but each sentence contributes value, with examples of regressions adding clarity. It is front-loaded with the core comparison action. While not as terse as the highest standard, it is efficient and well-organized.

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 no output schema and no annotations, the description explains the return semantics (ranked alerts, status) and the tool's use case (refresh validation). It does not mention prerequisites like prior snapshot creation (sibling sentinel_snapshot), but for a two-parameter pure function, the coverage is strong.

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%, and the schema already defines beforePath and afterPath clearly as BEFORE and AFTER snapshot JSON paths. The description adds only minor context ('before vs after a refresh', 'two snapshot files'), which does not materially augment the schema. Baseline 3 is appropriate.

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 uses a specific verb ('compare') and resource ('two integrity snapshots'), clearly differentiating from siblings like sentinel_snapshot (which likely creates snapshots) and quality_gate. It explicitly states the before/after refresh context, making the tool's purpose unmistakable.

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 clearly indicates when to use the tool ('before vs after a refresh') and provides a critical interpretation guideline ('status=fail means a report is now WRONG - do not trust the refresh'). However, it does not explicitly name any alternatives or state when not to use it, which would elevate it to a 5.

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