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

Annotations already declare readOnlyHint=true and openWorldHint=false, and the description is consistent with a pure, local transformation. The parenthetical '(heuristic)' is genuinely useful added context because it warns the agent that detection is pattern-based and may miss secrets, but nothing is said about whether the original text is returned redacted, how matches are replaced, or whether output is guaranteed idempotent.

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 sentence with the action, targets, and input type, plus a one-word caveat that earns its place. Nothing is redundant or padded.

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 simple one-string pure function, the description covers the operation and flags heuristic limits. Because there is no output schema and no statement of the return value (redacted string vs. list of findings), an agent still has an unanswered question about what comes back.

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 0%, but there is only one required string parameter named 'text', which is nearly self-documenting. The description contributes the useful framing that the input is a log string, yet it adds no detail about size limits, multi-line handling, or encoding expectations.

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?

Specific verb ('Remove') plus specific targets ('credential, email and phone patterns') applied to a named resource ('a log string'), so the agent knows exactly what the tool does. It does not need sibling differentiation because the neighboring tools are unrelated utilities, but it also never contrasts itself with them.

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?

Usage is implied (sanitize a log line before sharing or storing it) but never stated. There is no explicit when-to-use, when-not-to-use, or note about what to do for structured/non-string inputs, so the agent must infer the call context.

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