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

Beyond the annotations, the description adds important effects: visibility is limited to synced contacts for 24 hours, recipients are auto-built unless a status sub-list is passed, and "this triggers delivery and cannot be undone." This is meaningful non-idempotent, irreversible behavior. The mention of statusJidList is slightly confusing because that parameter is absent from the schema, but no direct annotation contradiction is present.

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 tightly packed: initial action, visibility/recipient behavior, enter constraints, channel role, and safety warning are each one to two clauses, no unnecessary expansion. The first sentence gives the core purpose and each subsequent sentence adds only behavior the schema/annotations do not provide.

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?

It covers why and how to use the tool and warns about irreversibility, but it does not specify the returned result/acknowledgment shape (no output schema) or explicitly tell the caller to set messageType to image/video/audio when media is being posted. These are moderate gaps for a tool with six optional params, but strong too far above a minimal def.

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?

The schema coverage is 100%, so the baseline is 3. The description adds one genuinely useful constraint—"Provide at least one of text or mediaUrl"—and confirms channelId auto-resolution, but the latter is already in the schema. It also references statusJidList, which is not listed in the schema and would be rejected under additionalProperties: false, so the description introduces a parameter-semantics inconsistency.

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 opens with a specific verb-resource pair: "Post a WhatsApp Status / Story from a connected direct (Baileys) WhatsApp number." This clearly differentiates it from message-sending and broadcast siblings by emphasizing the Status/Story domain and the no-recipients delivery model.

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?

It gives clear context: the tool targets WhatsApp Status, does not let the caller specify recipients, and auto-resolves channelId to the default connected number. It does not explicitly name an alternative tool for when a recipient-targeted message is needed, but the exclusion is strongly implied by the status-specific wording.

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