get_msg

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

With no annotations supplied, the description carries the full burden, and it usefully declares the safety profile itself (只读 / read-only), which is the key trait an agent needs. It does not disclose error behavior for a missing/invalid message_id or any rate/scope constraints, so it is adequate but incomplete.

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 very short clauses, front-loaded with the action and key, and nothing redundant. It is efficient; it could be marginally richer without losing its compactness.

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 single-parameter read tool with 100% schema coverage and no output schema, the description goes slightly beyond the minimum by naming the return payload (original message text and sender). The remaining gap — what happens when the message is absent — is minor at this complexity level.

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% — the single message_id parameter is fully documented in the schema (integer, non-zero, sourced from an event). The description only restates that the lookup is by message_id, adding no format or constraint information beyond the schema, 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 states a specific verb (取/fetch) and resource (一条消息/a single message), plus the retrieval key (按 message_id) and the returned fields (原文与发送者). This clearly separates it from write siblings like delete_msg and from list-style siblings, though it never names the closest alternative (get_forward_msg) explicitly.

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 such as get_forward_msg or the get_*_list tools, and no prerequisites or prerequisites noted beyond the key name. Usage is only weakly implied by the parameter mention.

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