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

There are no annotations, so the description carries the responsibility for behavioral disclosure. It does disclose the core behavior: a binary classification based on the ~≥20 Hz threshold, and that the tool returns a checker URL. It does not clarify edge cases or what the URL contains, but it is substantially transparent for such a simple tool.

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 sentence that front-loads the input condition and states both the decision and the output type. Every element is necessary and there is no redundancy or filler.

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 one numeric parameter, no output schema, and no annotations, the description is mostly complete: it specifies the decision rule and the return value type. Minor gaps remain around the exact nature of the 'checker URL' and the fuzziness of '~≥20 Hz', but these are not critical for a simple classification tool.

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 already fully documents the hz parameter with 100% coverage, so the baseline is 3. The description adds useful context by linking hz to the headphone-vs-PEMF threshold, but it does not introduce new parameter format details or constraints.

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 states a specific decision operation: given a Hz value, determine whether headphones can play the fundamental (~≥20 Hz) or whether a PEMF coil is required. This clearly differentiates the tool from siblings like get_frequency or compare_frequencies, which serve different 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?

The description gives a clear trigger ('Given a Hz value') and intended outcome, so an agent can infer when to use it. However, it does not mention any sibling alternatives or explicitly state when not to use this tool, leaving the selection guidance mostly implied.

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