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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is known. The description adds valuable behavioral context that soft-deleted contacts are excluded, which goes beyond the annotations. This is useful behavioral transparency for a read-only list tool.

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 sentences with no filler. Every piece of information is meaningful and front-loaded. 'List all contacts in the household' immediately conveys the core function, and the note about soft-deleted contacts is concise and relevant.

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 simple list tool with no parameters, an output schema, and strong annotations, the description is fully complete. It states the resource, scope, and filtering behavior. The presence of an output schema means return values need not be described. No additional context is necessary.

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 has zero parameters, so the schema already fully describes it (100% coverage). The description redundantly states 'Takes no parameters,' but since there are no parameters to explain, the baseline of 4 applies. The description adds no further parameter semantics needed.

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 clearly states the tool's function: 'List all contacts in the household.' The verb 'list' and the resource 'contacts' are specific, and the scope ('in the household') distinguishes it from other list tools like list_house_members or list_appliances. The addition about soft-deleted contacts further clarifies its purpose.

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 implies clear usage context: use this tool to retrieve all non-soft-deleted contacts for the household. It does not explicitly name alternatives or exclusions, but given the straightforward nature of the tool and the sibling list, the context is sufficiently clear. A score of 4 reflects clear context without explicit alternative mentions.

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