hash_pbkdf2_hmac

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

With no annotations, the description carries full burden but provides minimal information. It does not disclose that PBKDF2 is computationally expensive, requires careful salt handling, or other behavioral traits like output format.

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 extremely short (4 words), which is efficient but lacks necessary detail. It is not overly verbose, but the brevity compromises completeness.

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 tool with 5 parameters, no schema documentation, and no annotations, the description is too sparse. Although an output schema exists, the description itself fails to provide enough context for proper use.

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 input schema has 5 parameters with 0% description coverage, and the description adds no meaning. Parameters like password, salt, iterations, dklen, hash_name are not explained (e.g., expected encoding, units, or valid ranges).

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 'PBKDF2-HMAC key derivation' clearly identifies the tool's purpose as key derivation using PBKDF2-HMAC. However, it does not differentiate it from sibling tools like hash_scrypt, which also performs key derivation.

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?

No guidance is given on when to use this tool versus alternatives like scrypt or other hash functions. The description does not mention context, prerequisites, or exclusions.

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