password_check

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

Beyond annotations, description explains k-anonymity mechanism (5-char prefix), that full hash never leaves tool, rate limits (100/hr free, 1000/hr Pro), and return structure {found, count}. 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?

Concise (3-4 sentences), front-loaded with primary action. Minor room for improvement with more structured layout, but effectively communicates key points.

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?

Covers purpose, usage, behavioral details, rate limits, and return values. Output schema exists to document return format. Rich annotations complement the description.

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?

Input schema already fully describes the parameter with an example. Description adds context about k-anonymity and rate limits, going beyond baseline for high coverage.

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 checks if a SHA-1 hash appears in HIBP using k-anonymity, and distinguishes from sibling tools like hash_lookup, email_disposable, and username_lookup by contrasting their namespaces and purposes.

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?

Explicitly states use case (password breach audits), notes read-only nature, and lists alternative companion tools with their specific functions, guiding when to use each.

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