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

With no annotations, the description carries the full burden of behavioral disclosure. It does state that it returns a hex digest and documents the default keylen of 32, but it omits input encoding expectations, error behavior, and security properties. Adequate but minimal.

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 concise sentence that front-loads the core purpose before adding output details. The minor redundancy of repeating 'password and salt' is the only inefficiency.

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?

This is a security-sensitive crypto tool with no annotations, no output schema, and an empty input schema, so the description must explain how to invoke it correctly. It covers the algorithm, inputs, and return format, but not how the password/salt should be passed given the empty schema, nor encoding or keylen semantics. This is insufficient for reliable invocation.

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?

The description names all effective parameters (password, salt, keylen) and specifies the default keylen, which adds meaning beyond the empty schema. However, because the schema declares zero properties, the described parameters are not represented in a usable way, leaving the agent unsure how to actually pass them.

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 uses a specific verb ('Derive') and a specific resource ('scrypt password hash'), and names the exact output ('hex digest'). The 'Scrypt:' prefix clearly distinguishes it from the many sibling crypto and hash tools.

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 tells the agent to 'Provide password and salt' and mentions an optional keylen, giving a basic invocation pattern. However, it gives no guidance on when to choose scrypt over alternatives like pbkdf2, and the instruction conflicts with the empty input schema.

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