format_duration

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

With no annotations, the description carries full burden. It discloses the input unit and output format, but does not specify behavior for edge cases (negative, zero, large values) or locale/numerals effects beyond schema defaults.

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 a single sentence with an example, which is efficient and front-loaded. Minimal but no wasted words; the example aids understanding.

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 formatting tool with no output schema, the description adequately explains input (milliseconds) and output (Arabic words). It covers the main purpose, though could mention return type or handle more edge cases.

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 baseline is 3. The description provides an example but adds no extra meaning to parameters beyond what the schema already describes for 'value', 'locale', and 'numerals'.

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 formats a duration in milliseconds to natural Arabic words, with a concrete example. It distinguishes from siblings like 'arabic_ordinal' and 'format_relative_time' which handle different formats.

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?

No explicit guidance on when to use this tool versus alternatives like 'format_relative_time'. The description implies its use for Arabic duration formatting but lacks 'when not to use' context.

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