truncate

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

Beyond the destructiveHint annotation, the description details the destructive nature: 'Destructive: modifies file content — shrinking discards data, extending fills with null bytes.' It also explains the dry-run preview and return format (JSON with old and new file size). No contradiction with annotations.

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 concise and well-structured: first sentence states the core action, then a warning, then usage, then exclusions, then references. Every sentence adds value, and the most critical information is front-loaded.

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?

Despite no output schema, the description covers all key aspects: behavior (including dry-run and destructive), parameters' roles, return format (JSON), and alternative tools. This is complete for an agent to select and invoke correctly.

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?

The schema already fully describes all 5 parameters (100% coverage). The description adds contextual meaning by explaining the effect of size (discard/fill) and the purpose of dry_run (preview). While baseline is 3, the description reinforces and clarifies the overall behavior, earning a 4.

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 action: 'Shrink or extend file sizes to an exact byte length.' It uses a specific verb and resource, and distinguishes from siblings by explicitly saying 'Not for timestamp-only updates — use 'touch'. Not for block-level copying — use 'dd'.' This provides clear differentiation.

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 provides explicit when-to-use ('Use to resize files programmatically') and when-not-to-use ('Not for timestamp-only updates', 'Not for block-level copying') along with named alternatives ('touch', 'dd'). This gives clear guidance for selecting this tool over siblings.

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