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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered. The description adds only 'Returns converted temperature,' which is minor and covered by the output schema; it does not disclose precision, rounding, or invalid-input 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 short and front-loads the core purpose and use cases. However, the 'Inputs: value, from, to' and 'Returns converted temperature' sentences duplicate information already present in the input and output schemas, slightly reducing efficiency.

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?

Given the simple conversion task, full schema coverage, and an existing output schema, the description covers purpose, typical use cases, inputs, and a related-tool pointer. It is nearly complete, though it does not address edge cases such as invalid units or precision handling.

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 the schema already documents value, from, and to, including enums for units. The description merely lists the same input names without adding format, range, or conversion semantics beyond what the schema provides, making the baseline 3 appropriate.

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 and resource: 'Convert temperature between Celsius, Fahrenheit, and Kelvin.' It clearly distinguishes itself from other conversion siblings like convert_angle, convert_area, and convert_weight by naming the exact units and resource.

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?

Provides clear contexts for use: cooking, weather, and science. It does not explicitly state when not to use it or name alternatives, but it points to list_bundles for related conversion calculators, giving adequate routing guidance for a simple conversion tool.

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