read_message

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

The description discloses the key side effect of marking the message as read (ack), which is beyond the tool name. However, with no annotations provided, it doesn't disclose the return format, permission requirements, or error behavior. It adds some context but leaves significant gaps.

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?

One sentence, directly states the action and side effect. No fluff, front-loaded with the verb.

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 no output schema and no annotations, the description is too thin. It omits what the tool returns (e.g., message content) and what agent_id is used for. The side effect is clear, but the overall context is incomplete for an agent to invoke it correctly.

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%, and the description doesn't mention either parameter at all. It doesn't explain the purpose of agent_id or the format/requirements for message_id, so the agent must rely solely on the schema, which has no descriptions.

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 clearly states the action ('fetch') and the resource ('a message'), and adds a precise side effect ('mark it read (ack)'). This distinguishes it from siblings like get_thread (which fetches without ack) and mark_unread (which reverses the read state).

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 implies the tool is for fetching a message while also acknowledging it, but it doesn't explicitly mention alternatives or when not to use it. Sibling tools like get_thread or search_messages could serve for reading without the ack side effect, but no comparison is given.

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