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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states 'parser' and 'validator' but does not explain what the tool returns on valid or invalid input, whether it normalizes the address, or if it throws errors. The agent has no information about the tool's output format or error behavior.

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 concise, one sentence with no wasted words, and the core purpose is front-loaded. It could benefit from additional context, but it is efficient and directly states the tool's function. It does not contain unnecessary 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?

The tool is simple with one parameter and an output schema, so the description may not need to detail return values. However, it lacks any information about validation behavior, error cases, or what the output represents (e.g., boolean, normalized string, parsed components). Given the availability of several similar MAC tools, this missing context could lead to incorrect tool selection.

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 schema has a single 'q' parameter with 0% description coverage, so the description must clarify its meaning. While the description implies that 'q' is the MAC address to validate (by mentioning accepted formats), it does not explicitly state this or explain the expected input format beyond listing separators. This is insufficient compensation for the lack of schema documentation.

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 identifies the tool as a MAC address validator and parser, mentioning accepted formats (colon/dash/plain). This distinguishes it from sibling tools like macvendor or macvendorlookup, which likely focus on vendor lookup. The verb 'parser' and resource 'MAC address' are specific and unambiguous.

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?

There is no guidance on when to use this tool versus alternatives such as mac, macvendor, or macvendorlookup. The description does not mention any specific use cases, prerequisites, or conditions that would make it preferable over other MAC-related tools. An agent has no basis to choose this tool over its siblings.

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