Acknowledge messages

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

With no annotations, the description carries the full behavioral burden. It usefully discloses that 'History is kept' – i.e. acknowledgment is non-destructive – but is silent on auth requirements, idempotency, and how already-acknowledged or invalid ids behave.

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 short sentences with the core action front-loaded; the 'History is kept' clause is informative rather than filler. 'for an agent' is slightly redundant against the schema's agent parameter, but overall it is tight.

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 2-parameter mutation tool with no annotations and no output schema, the description conveys the action and its effect. It leaves behavioral edge cases (idempotency, auth, error conditions) uncovered.

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 both parameters are already documented in the schema. The description adds no syntax or format detail beyond that, 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 and resource ('mark messages as handled') and pins down the concrete effect ('drop out of the unread inbox'), which distinguishes this from bridge_inbox and bridge_send. It does not explicitly name a sibling alternative, so it falls short of full differentiation.

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 phrase 'so they drop out of the unread inbox' implies when to use it (clearing unread messages), but there is no explicit when-to-use vs when-not guidance, no prerequisites, and no named alternative such as bridge_inbox.

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