mark_read

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the primary side effect (marking messages read) but does not disclose whether this affects all chat participants or only the current user, whether the action is reversible, or any permission requirements. This is minimal at best.

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 description is a single, clear sentence with no redundancy; it is concise and front-loaded with the action. It could carry slightly more useful context without harming brevity, but it does not waste words.

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 tool with a single parameter and an existing output schema, this description is minimally sufficient to understand the basic action and invoke it correctly. However, it lacks usage context and behavioral caveats, and with a confusable sibling present, an agent might not reliably choose this tool over alternatives.

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 the unidentified 'chat' parameter. The phrase 'in a chat' indicates that the parameter identifies a chat, but it does not specify whether the value should be a chat ID, name, or another identifier, nor the expected format.

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 uses a specific verb ('mark') and resource ('all messages in a chat as read'), making the core action clear. However, it does not explicitly differentiate from the sibling tool 'read_messages', which could be interpreted as the same action; a brief note that this tool does not fetch message contents would remove ambiguity.

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?

There is no guidance on when to use this tool versus alternatives like 'read_messages' or 'list_chats'. The description only states what it does, leaving the agent to infer appropriate use cases without any exclusions, prerequisites, or context.

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