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

The description adds substantive behavioral context beyond the annotations: it explains the tool does not execute the file, performs local inspection, and returns specific decision types (allow, notice, confirm, block). This complements the readOnly/idempotent hints with concrete operational details, and there is no contradiction with annotations.

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 sentence that front-loads the core action ('Inspect a Base64-encoded file locally') and efficiently conveys the purpose, safety, and policy aspects without redundant words. Every phrase earns its place.

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, the description covers essential aspects: what it does, how it behaves (no execution), the decision output, and policy options. The output schema exists, so return values are already documented. The description is sufficient for an agent to understand 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 coverage is 100%, so the baseline is 3. The description does mention the policy options and default, but this largely restates the schema's enum description. It adds minimal information beyond what the schema already provides for filename/content_base64, so no higher score is warranted.

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 function: inspect a Base64-encoded file locally for structural and security risk signals without executing it, and return a policy-aware decision. It distinguishes itself from siblings by focusing on file inspection and explicitly noting non-execution, which differentiates it from tools like inspect_command or analyze_url_risk.

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 clear context on when to use the tool—for evaluating a Base64-encoded file's risk locally without execution—and mentions the policy parameter. However, it does not explicitly name alternatives or state when not to use it, so it lacks the explicit exclusions that would merit a 5.

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