mark_messages_read

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

With no annotations, the description carries the full behavioral burden, and it usefully discloses that confirm=true is required despite the schema defaulting it to false. However, it says nothing about permissions/auth, whether the change is reversible, batching limits on message_ids, or what happens with unknown IDs.

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 operation front-loaded and the prerequisite immediately following; no filler. It is perhaps over-terse given the total absence of annotations, but every sentence earns its place.

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?

An output schema exists, so return values needn't be described, and the mutation is simple with only two parameters. Still, for an unannotated write operation the description is thin — missing side-effect, idempotency, and permission context an agent would want before calling.

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 0%, so the description must compensate for both parameters. It clarifies confirm's semantics (must be true even though the schema defaults to false), which is real added value, but message_ids is entirely unexplained — no format, limits, or behavior for invalid IDs.

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+resource combination ('Mark inbox messages as read') that clearly identifies the operation and the object it acts on. It does not explicitly contrast with the closest sibling, delete_messages, but the distinction is inferable.

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 one hard prerequisite ('Needs confirm=true'), which is actionable, but offers no when-to-use vs when-not guidance and no mention of the sibling delete_messages. Usage is implied by the verb rather than stated.

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