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

No annotations are provided, so the description carries the full burden. It does disclose one behavioral trait — "input discarded" — but says nothing about return format, determinism, auth, or why nine unrelated inputs are accepted.

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?

Brief and front-loaded, but the brevity is under-specification rather than economy. Four words cannot carry a nine-parameter tool, so the terseness is a defect, not a virtue.

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?

Nine optional parameters, no annotations, and no output schema, yet the description is a single fragment. Nothing explains what the tool returns or how the heterogeneous inputs are used, leaving an agent without enough information to invoke it confidently.

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 description coverage is 100%, so the baseline is 3. The description adds only the note that inputs are discarded, which matches the schema's own hints and adds little beyond what the per-parameter text 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?

"PBKDF2 hex length" gestures at a resource but names no verb and leaves the operation ambiguous (compute? return? validate?). Combined with nine unrelated parameters, an agent cannot tell what the tool actually does or how it differs from siblings like calc-eval or search-query-len.

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 when-to-use, when-not-to-use, or alternative is mentioned. The four-word description offers nothing to help an agent choose this over any of the ~29 sibling tools.

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