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

readOnlyHint=true already tells the agent this is a safe read, so the description is off the hook for safety. It adds only the underlying API path; nothing about behavior when the id is unknown (404/empty), auth requirements, or what the response contains.

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 short sentences, purpose front-loaded, no filler. The endpoint clause is marginal but aids debugging/mapping to the DoorLoop API.

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 tool with annotations covering safety, this is close to sufficient, but with no output schema the agent gets no hint about what a 'unit' record returns and no error behavior is described.

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% and already documents that unit_id comes 'from the matching list tool' (i.e., doorloop_list_units). The description adds nothing beyond that, which is acceptable given the schema already carries the semantics — baseline 3.

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 ('Get one unit by id'), and the 'one' plus the required id makes it distinguishable from doorloop_list_units. The underlying endpoint (GET /units/{unitId}) reinforces that this is a single-resource read, though the sibling is never named explicitly.

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 implication is that this is the detail-fetch counterpart to doorloop_list_units, but the description never says so or states when-not to use it. Usage is inferable from 'by id' rather than explained.

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