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

No annotations are provided, so the description carries the full behavioral burden. It usefully discloses the cost model ($0.003 per call, USDC on Base), which is important beyond the schema, but it omits whether the function is pure/side-effect-free, how invalid input is handled, and any authentication requirements beyond payment.

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?

A single, front-loaded sentence with no redundant clauses. The cost parenthetical is compact and earns its place by conveying billing information.

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 utility with no output schema, the description does state the output style ('KB and MiB values'), which is helpful. However, it leaves the input parameter type unclarified and does not explain edge cases, so it is only minimally complete.

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 0%, and the single parameter 'bytes' is completely undocumented in the schema. The description only repeats 'a byte count' without specifying type, units, sign handling, or allowed format, adding almost no meaning beyond the parameter name.

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 states a specific verb ('Format') and resource ('a byte count') and names the output format ('human-readable size with KB and MiB values'). This is clear enough to distinguish it from all sibling utilities like tk_detectEncoding or tk_graphemeCount.

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 explains what the tool does but gives no guidance on when to use it versus alternatives, nor any preconditions or exclusions. Usage is only implied by the verb 'Format'.

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