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

Goes well beyond the annotations by disclosing atomicity (at most 20 patches, all-or-nothing), refusal behavior with reasons (non-text pointer refused with the path named; published flows cannot be patched), that ${...} bindings are left untouched, and the optimistic-concurrency role of lock_version. These are exactly the operational traits annotations can't express.

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?

Front-loaded with purpose, then pointer format, then refusals, then the lock_version requirement. Every sentence is load-bearing, though the dense single-paragraph form is slightly heavy for the amount of guidance given.

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?

Covers mutation semantics, atomicity, and concurrency adequately for a destructive write tool with no output schema. The one gap is what a successful call returns — an agent doing sequential patches would want to know whether a fresh lock_version comes back.

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?

With 0% schema coverage the description carries the full burden, and it does most of it: it explains that each patch is a JSON pointer plus a replacement string, shows how to build the pointer from get_whatsapp_flow, and defines lock_version's purpose. flow_id is left implicit, but it is self-evident from the parameter name.

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 (rewrite) and precise resource (wording inside a WhatsApp Flow draft), and explicitly bounds scope with 'and nothing else.' An agent can distinguish it from publish_whatsapp_flow, deprecate_whatsapp_flow, delete_whatsapp_flow, and the create/get siblings without opening any schema.

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 clear prerequisites and when-not conditions: the pointer must land on a text property, the flow must be a draft, and a lock_version from get_whatsapp_flow is mandatory. It also names the source tool for pointers. It stops short of naming an explicit alternate tool for the disallowed cases (e.g. superseding a published flow), leaving that inference to the agent.

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