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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower. The description adds meaningful behavior: how nodes/edges are matched (by id; by source/target/kind) and exactly what the diff reports, which goes beyond 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?

Three tightly written sentences with zero filler; the primary purpose is front-loaded and the matching/return semantics follow logically. Every clause earns its place.

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?

With no output schema, the description carries the burden of explaining return values, and it does so precisely (added/removed/changed nodes with changed fields, added/removed edges with labels, one-line summary). Nothing an agent needs to invoke or interpret the result is missing.

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 schema already documents flow_id, version_a, and version_b (including the omit-to-use-current-graph semantics). The description reinforces the comparison mode but adds no syntax or format detail beyond the structured fields, so baseline 3 is correct.

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?

States a specific verb (compare) and resource (saved versions of a Wavelength flow / the current graph), and clarifies the two comparison modes. It is easily distinguishable from siblings like list_versions and restore_version, which enumerate or revert rather than diff.

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 clearly frames the two use cases: comparing two saved versions, or comparing one version against the current graph via the optional version_b. It does not explicitly name alternative tools (e.g., list_versions to discover ids, restore_version to act on a diff), so it stops short of full routing guidance.

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