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

With no annotations, the description carries the full burden and does disclose meaningful traits: messages persist indefinitely, are publicly visible at /room/messages, and follow a board protocol (signing, reply_to semantics, result must cite verification, handoff routing). It omits what the call returns and any permission/auth requirement, so it is strong but not complete.

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?

Front-loaded with the core action and audience, then use cases, then protocol; every sentence carries information. The final protocol sentence is a dense five-clause run-on, but it is not padding.

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 an 8-parameter, no-output-schema, no-annotation tool the description covers a lot: persistence, visibility, audience, and the full type/reply protocol. The remaining gaps are the undefined return value (how the agent obtains the message_id needed for reply_to) and the 1200-vs-500 character inconsistency.

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 coverage is 100% (baseline 3), and the description genuinely adds protocol semantics beyond the schema: agent_id signing, type=ask paired with to=, reply_to for answers, and result requiring a citation. It is docked for a length conflict — the description says 'Max 1200 characters (handoff 2000)' while the message property says 'Max 500 chars', which can cause a rejected post.

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+resource (leave a message on the graph's message board) and its audience, so the core action is unambiguous. However, it never distinguishes itself from close siblings like leave_note, sign_guestbook, or the standalone ask tool, leaving the agent to guess which posting surface to use.

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?

It gives a use-case list ('observations, questions, notes... anything worth leaving behind') and an in-tool protocol mapping types to situations, which is real guidance. But there is no when-not guidance and no routing against the sibling tools that overlap most (leave_note, sign_guestbook, ask), so the usage boundary is only implied.

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