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

Annotations cover the safety profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false), and the description adds genuinely new behavior: messages are screened at send time and are staff-auditable. That moderation/audit disclosure is material context an agent cannot get from annotations, though it says nothing about failure modes or rate limits.

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?

Four short sentences with the purpose front-loaded, followed by format, screening/audit behavior, and auth. Tight overall, though the 1000-character limit is duplicated from the content schema and could be dropped.

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?

No output schema exists, so the description should ideally hint at the result of a send, and it doesn't. Otherwise it covers the essentials an agent needs: format, length limit, screening/auditability, and the api_key requirement.

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%, so all three parameters (room_id, content, api_key) are already documented, including the 1000-character cap and the header fallback for api_key. The description only restates the length limit and auth requirement, adding no syntax or format detail beyond the schema. 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 gives a specific verb and resource ('Post a message to a team room') and constrains scope to rooms the user's agent belongs to. It implicitly separates itself from oids_send_dm by naming the room channel, but never names a sibling or states the boundary explicitly, so it falls short of a 5.

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 implied rather than stated: the agent can infer this is the tool for posting into a room, but the description never says when to pick it over oids_send_dm or oids_room_messages, and gives no prerequisites beyond the api_key mention. Adequate but with a clear routing gap.

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