Delimit Diff

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 value beyond those by stating the operation is read-only, is a pure structural diff without policy, and specifically calls backends.gateway_core.run_diff. 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 front-loaded with the core purpose and organized into brief, scannable guidance sections. Every sentence contributes either to selecting the tool or understanding its behavior; there is no filler.

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 read-only annotations, an output schema, 100% parameter documentation, and clear routing to neighboring tools, nothing essential is missing. An agent can correctly decide when to call it and what inputs to provide.

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?

Input schema covers 100% of parameters with descriptions for old_spec and new_spec, so the baseline is 3. The description adds general context about the change set but does not need to repeat the parameter-level details the schema already provides.

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 first sentence names the exact action ('Diff two OpenAPI specs'), the resource ('OpenAPI specs'), and the output ('list all changes'), and immediately distinguishes it as 'pure diff, no policy.' It also contrasts with delimit_lint and delimit_diff_report, so an agent can tell it apart from its closest siblings.

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?

Provides an explicit 'When to use' section, a 'When NOT to use' section that names the CI alternative (delimit_lint) and reporting alternative (delimit_diff_report), plus a sibling contrast. This is unambiguous decision guidance, not merely implied.

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