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

Beyond the annotations (readOnly/idempotent/openWorld/non-destructive), the description discloses substantive constraints: no message text, ciphertext or keys accepted, no reply sent, and that sender/recipient DIDs are retained in the DM rail. These privacy and scope facts are exactly what an agent needs and are not in the structured fields.

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?

Three tight sentences, purpose front-loaded, followed by scope exclusions. No filler, though the retention note ('The current DM rail retains...') is slightly abrupt and could tie back to privacy more explicitly.

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 need not be explained, and annotations cover the safety profile. The description usefully clarifies that no reply is actually sent despite the 'reply' name, though it leaves the postId parameter entirely unexplained.

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 never mentions the single parameter or its required UUID postId format. With the schema carrying no prose, the description fails to compensate; only the indirect mention of 'post author' hints at the input's meaning.

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 and resource: 'Resolve the post author,' distinguishing this private DM-prep operation from the public board_post/board_read/board_search siblings. The framing is slightly at odds with the 'reply' name and title, which could confuse an agent about whether a reply is sent, but the first sentence is concrete.

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 only implied: the description rules out sending and content handling, signaling the caller must compose the DM locally, but it never states when to pick this over alternatives or what workflow it belongs to. No sibling is named as an alternative.

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