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

With no annotations, the description carries the full burden and does meaningful work: it discloses determinism, no network access (a real privacy-relevant trait), typed placeholder output, and the x402 price of $0.003. It stops short of describing the return shape, reversibility of placeholders, or behavior on oversized input, so it is strong but not exhaustive.

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?

Two dense sentences, front-loaded with the operation and its scope, followed by behavioral and pricing facts. No filler, no repetition of the tool name.

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 single-parameter text utility with no output schema, the description covers what gets redacted, how (typed placeholders), key behavioral guarantees, and cost. The main gap is not clarifying the returned artifact or the oversized-input boundary.

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% and the single required 'text' parameter is never mentioned in the description; the schema only supplies length bounds. The parameter is trivially inferable from the tool's purpose, but the description adds no syntax, format, or size guidance beyond what the schema already states.

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 ('Redact') plus an explicit enumeration of the target entities (emails, phone numbers, SSN-shaped strings, Luhn-valid cards, IPv4), which distinguishes it cleanly from every sibling utility (sha256, base64, keyword_extract). An agent knows exactly what the tool does without opening the schema.

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 by the enumerated PII categories, so an agent can infer when it is relevant, but there is no explicit when-to-use/when-not guidance and no mention of alternatives (e.g., token_risk or ai_detector, which touch adjacent concerns). Adequate but leaves routing to inference.

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