file_compare

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

Annotations already provide readOnlyHint=true, destructiveHint=false, idempotentHint=true, and openWorldHint=false, covering safety and idempotency. The description adds valuable context about output formats (text, JSON, or both) and that it provides '差异统计和详细对比' (difference statistics and detailed comparison), which goes beyond annotations. No contradiction with annotations exists.

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 appropriately concise with two sentences: one stating the purpose and output, and one providing an example. The example is helpful but could be more integrated. The structure is front-loaded with the core functionality, though it could be slightly more polished in flow.

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?

Given the tool's moderate complexity, rich annotations, 100% schema coverage, and presence of an output schema, the description is reasonably complete. It covers what the tool does and output formats, though it lacks usage guidelines and deeper behavioral context. The output schema likely handles return values, so the description doesn't need to explain them.

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%, with all parameters well-documented in the schema. The description adds minimal value beyond the schema, only mentioning output formats in the example without additional semantic context. The baseline of 3 is appropriate since the schema carries the full burden of parameter documentation.

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: '比较两个文件的差异' (compare differences between two files) with specific output formats. It distinguishes from siblings like file_edit (editing), file_hash (hashing), and file_search (searching), but doesn't explicitly contrast with file_operation which might be more generic. The description is specific about what it does but could more explicitly differentiate from similar file operations.

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 no guidance on when to use this tool versus alternatives. It doesn't mention when file_compare is appropriate versus other file tools like file_operation or file_search, nor does it specify prerequisites or constraints. The example shows usage but doesn't provide contextual decision-making guidance for the agent.

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