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

Annotations already declare destructiveHint=true, idempotentHint=true, and openWorldHint=true, so the safety profile is covered. The description still adds real value by disclosing that the edit propagates to 'everyone's change stream', i.e. the mutation is publicly visible and broadcast – context not derivable from the annotations alone.

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?

Two short sentences with zero waste. The core action is front-loaded and the side-effect disclosure follows immediately, with no redundant restatement of the title or annotations.

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 mutation tool with no output schema, the description covers the action and its public broadcast effect, and annotations cover destructiveness and idempotency. It still omits what happens to the previous text, error/ownership-failure behavior, and the 'id' format, leaving gaps an agent may hit in practice.

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 only 33% (only 'token' is documented). The description implicitly maps 'text' to the replacement content and 'id' to the target post, partially compensating, but it gives no format, length, or lookup guidance for those two undocumented parameters, so the gap is only partly filled.

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 ('Replaces the text of one of your own posts'), which cleanly separates it from siblings like rssa_board_delete and rssa_board_post. The ownership qualifier ('your own') further narrows scope, though no sibling is named explicitly.

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: an agent can infer this is the tool for modifying an existing post's text. There is no explicit when-not guidance, no mention of prerequisites (e.g., you must own the post), and no routing versus alternatives such as delete-then-repost.

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