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

Annotations declare readOnlyHint=false, destructiveHint=false, so the description adds substantial value beyond them: it discloses that saving affects future turns, sends no message, requires idempotency handling, and mentions REVISION_CONFLICT handling. This is rich behavioral context beyond the structured fields.

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 long but every sentence carries essential information: prerequisites, effects, consent, retry, and post-check. It is structured logically and front-loads the main action. It could be tightened but remains efficient for the complexity.

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 tool's complexity (nested updates, idempotency, conflict handling, consent), the description covers prerequisites, update semantics, persistence, no-message effect, and error recovery. An output schema exists, so return values need not be explained. Nothing critical is missing for correct invocation.

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 only 40%, so the description compensates. It explains idempotencyKey reuse, expectedRevision on retry, and that omitted fields in updates remain unchanged. It also directs resolving group IDs for audienceGroupIds. It does not detail every field, but it adds meaning beyond the schema for the key parameters.

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 description clearly states the action: 'Update the exact WhatsApp agent' – a specific verb and resource. It adds context by requiring a prior read and confirmation of the selected account, agent, and changes, which distinguishes it from read-only tools like get_whatsapp_agent and other resource update tools.

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 explicit usage conditions: must read first, confirm the exact changes, and resolve group IDs using list_contact_groups. It also states that omitted fields stay unchanged, requires fresh consent, and gives retry behavior on conflict – all clear guidance on when and how to use it.

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