Update device registry entry

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

Goes well beyond the annotations by disclosing the underlying WS call, the partial-update semantics ('only the parameters you pass are sent, so omitted or null fields are left unchanged'), the return shape, and a real constraint that area_id can be set but never cleared. These are behavioral traits an agent could not infer from readOnlyHint/destructiveHint alone.

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?

Front-loaded with the core action, then cleanly separated into WS/partial-update semantics, usage, return value, and limits. Every sentence adds information and none is redundant with the schema.

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 mutation tool with annotations, a full schema, and an output schema, this covers the partial-update behavior, the constraint on area_id, and the return shape. Nothing an agent needs to invoke it correctly is missing.

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 description coverage is 100%, so the baseline is 3, and the description earns a bump by adding the area_id limitation that the schema does not state (the schema only says 'omit to leave unchanged', not that clearing is impossible). The enabling/disabling hint also ties disabled_by to intent.

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?

States a specific verb and resource ('Update fields on an existing device registry entry') and clearly contrasts with siblings like devices_list_devices and devices_remove_device. An agent can tell what the tool does and roughly which registry object it acts on without opening the schema.

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 'Use when' clause gives concrete scenarios (renaming, moving to another area, enabling/disabling) that map directly to the available fields. It provides clear context but does not explicitly name alternative tools or state when NOT to use it, so it falls short of a 5.

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