Diff two texts

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds useful behavioral detail by specifying the output format ('unified diff'), the line-by-line granularity, and the special case of returning a note when inputs are identical. No contradiction with the 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 compact and front-loaded: it names the operation, the output format, and the special identical-input case in two sentences. Every sentence adds value, with no filler or redundancy.

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 read-only diff tool with an output schema and comprehensive annotations, the description is complete. It covers the core behavior, the use case, and the edge case of identical inputs. Nothing essential is missing for an agent to decide when and how to invoke it.

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 the parameters (before, after, context_lines) are already fully documented in the schema. The description adds high-level intent but does not introduce new parameter-level detail beyond what the schema provides. Baseline 3 is appropriate.

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 action and resource: 'Return a unified diff between two versions of a text, line by line.' It also clarifies the intended use case (comparing draft and revision) and notes the identical-input behavior. This clearly distinguishes the tool from siblings like summarize_text or text_stats.

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 clear context for when to use the tool: 'so edits between a draft and a revision can be reviewed precisely.' It does not explicitly name alternatives or exclusions, but the sibling tools are functionally distinct enough that the intended usage is evident.

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