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

Annotations already declare readOnlyHint=true and openWorldHint, so the read-only nature is covered. The description adds value beyond that by disclosing cost ('Free to call'), the recommended polling rhythm, and that results appear only after completion. It stops short of describing possible status values or error states, so it is strong but not exhaustive.

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 tight sentences, front-loaded with the core action and followed by cost, cadence, and completion condition. Nothing is redundant and every clause carries operational information.

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 one-parameter read-only poller with no output schema, the description covers purpose, cost, timing, and termination, which is most of what an agent needs. It could go slightly further by sketching the result payload or possible non-terminal statuses, but nothing critical 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 coverage is 100% and the single batch_id parameter is fully described there (UUID returned by whatsapp_batch_submit). The description adds no parameter-level detail beyond restating the source of the ID, so the baseline 3 applies.

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 (poll) and resource (status/results of a WhatsApp batch validation job) and ties it to the sibling that creates the job (whatsapp_batch_submit). An agent can distinguish it from the other whatsapp_* tool without opening the 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 concrete when-to-use guidance with polling cadences (5-10s for small batches, 30-60s for large ones) and the stop condition (until status is "completed"). It also names the originating tool, so the alternative path (submitting a new batch) is implicit and clear.

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