parse_user_agent

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

Annotations already mark the tool as read-only, and the description adds the detected categories, effectively serving as an output contract in the absence of an output schema. It does not disclose edge-case behavior for malformed or empty User-Agent strings, but it provides solid context beyond the annotations.

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?

Two sentences with no filler. The action and the detected fields are front-loaded, and every word adds value.

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 one-parameter read-only tool, the description clearly covers what it does and the main data it extracts. The only gap is the lack of explicit return-format details, but given the simple input and no output schema, the description is largely sufficient.

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 sole parameter, user_agent, is already fully documented by the schema (100% coverage). The description mirrors that with 'User-Agent string' and adds no format, examples, or edge-case details, so the baseline of 3 is appropriate.

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 names a specific verb ('Parse'), a precise resource ('a User-Agent string'), and the exact information extracted: browser name/version, OS, device type, and bot/crawler status. No sibling tool overlaps with this function, so it is unambiguously identifiable.

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 implies the natural use case—when you have a User-Agent string and want structured details—but it does not explicitly state when to prefer this tool over alternatives or mention any exclusions. The context is inferable rather than stated.

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