get_appliance_lifespan

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds value by specifying the return structure: 'lifespan range (in years)' and 'notes on factors that shorten or extend life.' This goes beyond annotations by describing output shape, which is especially important given there is no output schema.

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 exactly two sentences, front-loaded with the primary purpose and followed by a concise usage note. Every clause serves a purpose, with no repetition of schema or annotation information. It is appropriately sized for a simple lookup tool.

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 single-parameter, read-only tool with strong annotations and a clear schema, the description covers purpose, usage, and output characteristics. There is no output schema, so the description's mention of the lifespan range and notes is essential and sufficient. The tool is simple enough that no additional context is needed.

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 input schema has 100% description coverage for the single 'appliance_type' parameter, listing all supported values. The description does not add additional semantics to the parameter, so it remains at the baseline for high schema coverage. Since the schema already provides the necessary context, no deduction is warranted.

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 opens with a specific verb+resource: 'Return the expected lifespan range (in years) for a home appliance.' This clearly distinguishes the tool from siblings like calculate_repair_or_replace or get_maintenance_schedule by focusing on lifespan data. The inclusion of 'notes on factors that shorten or extend life' further narrows its scope.

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 second sentence explicitly states when to use the tool: 'Use this when a user asks "how long does X last" or is deciding whether to repair or replace an appliance.' This provides clear context, though it does not mention alternatives or exclusions. A sibling tool like calculate_repair_or_replace might also be relevant for repair/replace decisions, but the description does not address that distinction.

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