devices_get_by_fqdn

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It indicates a read operation ('Get') but does not explain behavior such as what happens when the FQDN is not found, whether the match is case-sensitive, or whether the FQDN is guaranteed unique. The example clarifies format but does not address runtime outcomes.

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, efficient sentence that states the operation, resource, and identifier, followed by a relevant example. No filler or redundant information; every word contributes to understanding.

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 simple one-parameter getter with no output schema, the description sufficiently communicates what the tool does and what input it expects. The absence of error-handling details is a minor gap for such a straightforward operation, but the core information needed to call it correctly is present.

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 already provides 100% parameter coverage with a clear description for 'fqdn'. The tool description adds value by giving a concrete format example ('hostname.domain.com'), which reinforces the expected input shape beyond the schema's 'Device FQDN'. This extra semantic clarity justifies a score above the baseline.

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 states the action: 'Get a single device' using a specific identifier, 'fully-qualified domain name (FQDN)'. This distinguishes it from sibling tools like devices_get_by_tachyon_guid and devices_search by specifying the exact lookup key. The verb-resource-scope structure is 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?

The description implies usage when you know a device's FQDN and need a single matching record, but it doesn't explicitly contrast with alternatives such as devices_search or devices_list. No exclusions or conditions are provided, so the guidance relies on inference rather than explicit routing.

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