Select entity option

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

Annotations already declare the safety profile (readOnlyHint=false, idempotentHint=true, destructiveHint=false), so the description needn't repeat that. It adds useful behavioral context by disclosing the service routing per domain and the return shape. It does not mention failure modes (e.g., an option that doesn't match configured options) or auth needs, keeping it short of a 5.

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 purpose, then service routing, then use/not-for, then return value. Every element earns its place, though the implementation detail about underlying service names is somewhat redundant with the clearly-named tool and adds a little length.

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 annotations covering the safety profile and an output schema covering the return value, the description only needs to establish purpose and routing. It does so completely, including the sibling alternative, leaving no gap an agent needs to call this 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?

Schema description coverage is 100%, so both parameters are already documented in the schema ('option must match one of the entity's configured options', entity ID format). The description adds no parameter-level detail beyond that, so the baseline of 3 applies.

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 ('Select an option') and resource ('input_select or select entity'), and further clarifies by naming the exact underlying service calls per domain. An agent can distinguish it from siblings like helpers_set_input_select without opening any 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?

Explicit 'Use when' clause defines the trigger condition, and the 'Not for' clause names the alternative (helpers_set_input_select) plus the condition selecting it (input_select-only call site). This is exactly the when/when-not/alternative structure expected at the top of the scale.

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