Get Value

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

Annotations already provide readOnlyHint=true and openWorldHint=true. The description reinforces that this is a read operation and adds that the tool reads a single datapoint. It does not contradict annotations and adds context about auto-resolution of interface, which is helpful 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?

The description is concise: only two sentences with no unnecessary words. The action ('Read a single datapoint value') is front-loaded, and every sentence serves a purpose.

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?

Given the tool's complexity (4 parameters, output schema present), the description is complete. It explains the tool's function, required parameters, and how to find valid inputs. No gaps in information needed for proper use.

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 coverage is 100% with descriptions for all 4 parameters. The description adds value by specifying that only address and valueKey are required and that interface is auto-resolved. It also directs users to other tools for finding valid values, which aids in correct parameter usage.

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 'Read a single datapoint value from a device channel.' It uses a specific verb (read) and resource (single datapoint value from device channel), and distinguishes from siblings like get_values (plural) and describe_device_type.

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 explicitly tells when to use this tool: 'Use list_devices to find addresses, describe_device_type to find valid valueKeys.' It also clarifies that only address and valueKey are required and interface is auto-resolved, providing clear guidance on prerequisites and alternatives.

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