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

No annotations are provided, so the description carries the full disclosure burden. It does add one genuinely useful behavioral fact — the 0.002 USDC cost — and 'screen' implies a non-destructive check, but it omits whether the call blocks the write, what happens on a failed screen, and any auth/payment requirements.

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?

A single front-loaded clause stating action, target, and criteria, with the cost appended. Every element earns its place and nothing is redundant.

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?

An output schema exists so return values need not be explained, but with zero annotation coverage, two undocumented nested-object parameters, and no guidance on failure handling or policy semantics, the description is too thin for a guard tool that gates writes.

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 0% for two nested-object parameters, and the description only loosely gestures at the 'write' parameter via the phrase 'persistent memory writes'. The 'policy' object is never mentioned, so the description does not compensate for the documentation gap.

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 gives a specific verb ('Screen') plus resource ('persistent memory writes') and enumerates the three checks performed (poisoning, unsafe instructions, missing provenance). It is clear what the tool does, though it offers no explicit contrast against potentially confusable siblings like tool_output_firewall or schema_normalize.

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?

There is no statement of when to invoke this guard versus alternatives, no prerequisites, and no exclusions. The price suffix hints this is a paid service (siblings include a *_free variant elsewhere), but the description never tells the agent to prefer a cheaper path or when screening is mandatory.

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