Head status

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds that the payload is the head module's live state fields, but says nothing about freshness/polling, whether values reflect the simulator's current tick, or what happens before a simulator is opened.

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?

A single front-loaded sentence naming the resource first and then the returned fields; no filler. It reads slightly like a schema dump rather than a purpose statement, which keeps it just short of a 5.

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?

With no output schema, the description carries the return-value burden and does list the fields, including the mode enum values. It is not fully self-contained: 'tracking phase' is left undefined (no enum values) and units/ranges for angle_deg and brightness are not given, but an agent can still call it correctly.

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 tool takes zero parameters, which is the baseline-4 case; there are no arguments whose meaning needs elaboration. The description's field list describes outputs rather than inputs, which is appropriate here.

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 the resource (head module) and enumerates exactly what state is read: angle_deg, target_deg, mode with its legal values, tracking phase, and head light brightness. That is enough to distinguish it from the generic get_observation/read_sensors siblings, but it never uses an explicit verb ('Get'/'Read') nor names set_head as the mutating counterpart.

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?

Usage is only implied: the tool is a status read for the head module, so an agent can infer it should call this before/after set_head. There is no explicit 'when to use this vs get_observation or read_sensors' guidance and no noted prerequisites or timing considerations.

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