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

With no annotations, the description carries full burden; 'Pure CPU, instant' usefully signals no network calls, no side effects, and no latency cost. It does not disclose what happens when from/to are omitted (defaults), whether the result is numeric or a formatted string, or how binary vs decimal is expressed, which are the real behavioral questions for this 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?

Two short sentences, zero filler, with the capability front-loaded and the performance characteristic trailing. Nothing is wasted or buried.

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 pure-computation converter with no output schema and full schema coverage, the description covers purpose and cost adequately. The remaining gap is the ambiguity around unit notation and default behavior for the two optional parameters.

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 coverage is 100%, but the schema descriptions are bare ('Target unit', 'Source unit', 'Size value'), so the description's mention of binary vs decimal units adds genuine meaning. It still does not explain how an agent selects binary versus decimal (e.g., 'MB' vs 'MiB'), nor what the optional from/to default to when only value is supplied.

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 between byte, KB, MB, GB and TB', which is immediately distinguishable from most siblings such as hash or base_convert. However it never differentiates itself from the closely related bytes_format, unit_convert, or data_rate tools, which an agent would plausibly confuse with it.

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?

'using binary or decimal units' implies the usage context, but there is no explicit when-to-use, no mention of when a different sibling (bytes_format, unit_convert) would be preferred, and no prerequisites. The guidance is inferable but not stated.

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