whatsapp_mark_message_read

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

Annotations already cover the safety profile (readOnly=false, idempotent=true, destructive=false). The description adds the visible effect ('blue ticks') and a privacy caveat, plus mention of a success confirmation—useful context for a mutation. It does not detail side effects like rate limits or idempotency mechanics, but that is minor given annotations.

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?

Two sentences, front-loaded with the primary action and immediately followed by the alternative. Every sentence earns its place with no filler.

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 four-param mutation with full schema coverage and annotations, the description covers purpose, alternative, effect, and return. No output schema exists, so mentioning the success confirmation suffices. It is largely complete, though idempotency is only in annotations.

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 description coverage is 100%, so the schema documents all four parameters, including an enum for receiptType. The description adds no parameter syntax or format details beyond what the schema provides, making 3 the 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 ('Send a read receipt for a message') and distinguishes from the sibling 'whatsapp_mark_chat_as_read' by name. An agent can tell exactly what this does versus the whole-chat variant.

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?

Explicitly routes the agent to 'whatsapp_mark_chat_as_read' for marking a whole chat, providing a clear when-to-use alternative. No further exclusions are needed.

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