mark_conversation_as_unread

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

With no annotations supplied, the description carries the full behavioral burden and does substantial work: it discloses the per-caller side effect, the 400 failure mode when the conversation has no messages, and the required `conversations:read` permission. Gaps remain on idempotency of repeated calls and on what a successful response contains.

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 functional sentence is front-loaded and dense with information (scope, mechanism, error case, permission). Minor waste comes from restating the tool name as a heading, plus the endpoint and 'Tags: Conversations' lines, which add little for an agent.

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 one-parameter mutation tool with no annotations and no output schema, the description covers the critical unknowns – side-effect scope, permission requirement, and an error condition – which is close to sufficient. It could be more complete with a sentence on the success response or on repeated invocation.

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 single `uuid` parameter is already fully documented by the schema (100% coverage) as the conversation path parameter. The description adds no meaning beyond that – no format examples, no note on what happens with an invalid or unknown UUID – 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?

The description pairs a specific verb and resource ('Marks the conversation as unread') with the exact mechanism ('moving their read position to just before the latest message') and the acting scope ('for the caller'). That level of detail lets an agent distinguish this from read-only siblings like get_conversation without inspecting any 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?

Usage is implied rather than stated: an agent can infer this is the tool to call when it wants a conversation to reappear as unread for the caller. There is no explicit when-not guidance, no mention of an opposite tool, and no note on whether this should precede or follow other conversation operations.

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