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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, and the description reinforces this with 'Saves nothing' — a genuinely useful disclosure that the generated alternatives are not persisted anywhere. It stops short of saying whether variants draw on brand voice/account context or how they are presented, but the critical non-persistence behavior is covered.

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 short sentences with zero waste: capability first, non-persistence second, then the routing example and the exclusion. Front-loaded and easy to scan.

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 read-only, single-parameter tool with no output schema, the definition covers what it produces (three alternatives), that nothing is saved, and when to prefer a sibling. Only minor gap is whether the returned variants are plain text only or carry any identifiers the agent could act on.

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?

Only one parameter, and the schema already documents it at 100% coverage ('Post id'). The description adds marginal value by framing it as an 'existing draft' and showing a concrete id in the usage example, but adds no format details beyond the schema baseline.

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 and resource ('produce three alternative versions of an existing draft') with a clear cardinality (three) and a scope limit ('to read'). An agent can immediately tell this apart from revise_draft and other draft-mutating 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?

Gives an explicit when-to-use example ('give me a few other versions of 123') and an explicit when-not-to-use case ('shorter', 'less salesy'), naming the correct alternative revise_draft and explaining how its behavior differs. Nothing is left to inference.

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