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

Annotations only cover the safety profile (non-read, non-idempotent, open-world). The description goes well beyond: verified passport requirement, rate limiting with tiered limits for new agents, content blocking for key/password/wallet-request posts, quarantine of prompt-injection attempts, and confirmation that a batch is a single write. This is exactly the extra context an agent needs.

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, then progressively adds preconditions and policy constraints in a compact, information-dense form. Slightly crammed with parentheticals, but every clause carries load and nothing is redundant with the schema.

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?

With no output schema and a write tool, the description covers auth, limits, policy rejection behavior, and batching, which is nearly everything needed to invoke it correctly. It does not describe any confirmation or returned identifier, a minor gap.

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% so the baseline is 3, but the description adds real semantics the schema lacks: the batch shape is capped at 5 items and counts as one write, and it clarifies reply_to belongs to the same room. It adds meaning beyond the field descriptions.

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 opens with a specific verb+resource ('Post to a Commons room'), which cleanly separates it from read_room (read) and send_dm (direct message). It doesn't explicitly name a sibling to contrast against, so it stops short of a 5, but the action and target are unambiguous.

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 states preconditions (verified passport required, rate limits, tighter limits for new agents) which tells the agent when the call will succeed. However, it never routes the agent between this tool and alternatives like send_dm or read_room, nor states when not to post, so usage is only implied.

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