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 covered. The description adds valuable behavioral context: the conversion runs in the user's browser (not server-side), and the tool returns a link that opens the converter with both formats chosen. This goes beyond what annotations provide.

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?

Three sentences with no waste. The core purpose is front-loaded, the format clarification is useful, and the browser-side note is a meaningful behavioral detail. Every sentence earns its place.

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?

The description is complete for a read-only, idempotent check tool with a clear output schema. It explains what the tool does, what the parameters mean, and the key behavioral trait (browser-side conversion). The only minor gap is not describing the output schema's structure, but the output schema exists and the description mentions the link and step count.

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 both parameters (from, to) are already documented with examples. The description adds the context that formats are file extensions like 'heic' or 'jpg', which reinforces but doesn't significantly extend the schema. Baseline 3 is appropriate since the schema does the heavy lifting.

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 purpose: checking whether a conversion is possible, how many steps it takes, and getting a link with formats pre-selected. It uses a specific verb ('check') and resource ('Convert To It'), and the mention of 'in how many steps' distinguishes it from a simple yes/no check. The sibling tools (list_conversion_targets, search_formats) are clearly different in 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 description implies when to use this tool: when you need to verify a conversion between two specific formats and obtain a link. It doesn't explicitly state when not to use it or name alternatives, but the context signals and sibling names make the use case clear. The phrase 'Check whether Convert To It can convert...' gives a clear context for use.

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