Mark chat as read

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

Annotations already declare this is a mutation (readOnlyHint=false), idempotent, and non-destructive. The description adds meaningful behavioral context beyond the annotations by explaining the unread counter reset and the externally visible effect that the contact may see blue ticks.

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 short sentences with no waste: the primary effect is front-loaded, followed by the user-visible consequence and the usage caution. Every sentence adds distinct 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 two-parameter mutation with full schema coverage and annotations that cover safety and idempotency, the description supplies the remaining important context: what changes, what the contact may observe, and when it should be invoked. No output schema is needed to explain return values here.

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%, and the schema already documents both the chat id number and optional instance_id. The description adds no parameter-specific syntax or constraints, so the baseline of 3 is appropriate.

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 states a specific verb and resource: marking unread messages of a chat as read and resetting its unread counter. It is clear enough that an agent can distinguish this action from messaging or chat-listing siblings 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?

The description gives an explicit usage condition: only after the user has actually handled the conversation. It does not name alternative tools or spell out when not to use it beyond that caution, so it falls short of full when/when-not/alternatives guidance.

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