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

Annotations already declare readOnlyHint=false, idempotentHint=false, destructiveHint=false, so the mutation profile is covered. The description adds real context beyond that: content is plain text capped at 100,000 characters, messages are screened at send time like DMs, and they are staff-auditable. That audit/screening disclosure is the kind of behavioral trait an agent would not otherwise know, though failure modes and rate behavior remain unstated.

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, front-loaded with the action and scoped with constraints. Each sentence carries information except the trailing api_key sentence, which partly duplicates the api_key property description ('omit if the Authorization header is set').

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 write tool with no output schema, the description covers format, size limits, screening/auditability and credential requirement, which is enough to call it correctly. Missing are the failure/return behavior and whether sends are rate-limited; annotations carry the safety profile.

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 room_id, content and api_key are already documented, including the 100,000-character limit and the 'from oids_list_rooms' hint. The description restates the format and length constraint but adds no syntax or format detail 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?

States a specific verb and resource ('Post a message to a team room'), which cleanly separates it from the DM siblings like oids_send_dm. It does not explicitly name an alternative tool, so it stops short of the top band, but an agent can identify the operation immediately.

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: posting into a room the user's agent belongs to, with room_id sourced from oids_list_rooms. There is no explicit statement of when to choose this over oids_send_dm or oids_publish_post, and no exclusions or prerequisites beyond the api_key note.

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