List sub-compositions (structure + current values)

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

Annotations already provide readOnlyHint, idempotentHint, destructiveHint; the description adds that it is a 'convenience read' and explains what it returns (joined model and state), plus mentions return format options. No contradictions, and the description enriches annotations with specific behavior.

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 two short paragraphs with no fluff. First paragraph explains the tool's purpose and return structure, second lists args and return format. Front-loaded and efficient.

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?

Despite having no output schema, the description explicitly provides the return structure with nested fields (subCompositions containing nodes). Combined with 100% parameter coverage and clear annotations, the description is complete for the tool's complexity.

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%, so baseline is 3. The description adds minimal extra meaning beyond the schema: it notes that 'app' is preferred over 'appToken', which is a useful nuance, but does not provide new details for each parameter.

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 states a specific verb ('joins') and resource ('model + live control state'), and explicitly lists the returned fields (id, title, type, current value). It distinguishes from sibling tools like singular_get_model and singular_get_control_state by noting it combines both.

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 clearly advises when to use this tool ('best single call to understand what can I fill and what's in it now'). It implies usage context but does not explicitly state when not to use or name alternatives, though the sibling list provides those hints.

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