vrchat_group_post_update

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

Beyond the minimal readOnlyHint: false annotation, the description richly discloses non-obvious behavior: VRChat replaces the whole post, the tool reads the most recent 300 posts to recover omitted fields, older posts cannot preserve roleIds/imageId, mergedFromExisting: false is reported, and editing does not re-notify members unless sendNotification is true.

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?

The description is dense but every sentence earns its place. Core update behavior is front-loaded, followed by merge-window caveats, the response flag, and notification behavior. There is no filler or repetition of schema data.

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?

Given the output schema exists, the description need not enumerate return fields. It covers the critical operational context: partial updates, the 300-post recovery window, fallback behavior for older posts, the mergedFromExisting response flag, and the notification toggle. An agent has everything needed to call this safely and interpret edge cases.

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 schema already documents every parameter. The description adds meaningful update-specific semantics beyond the schema: omitted fields retain current values, roleIds: [] clears restrictions, and the notification side effect is tied to sendNotification. This exceeds the baseline for high schema coverage.

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 'Update a group post', a specific verb and resource, and immediately clarifies partial-update semantics ('Omitted fields keep their current values'). This clearly separates it from sibling create/delete operations without needing to inspect schemas.

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?

The description makes clear this tool edits an existing post identified by postId, and explains the merge behavior for omitted fields. It does not explicitly name alternatives like vrchat_group_post_create or vrchat_group_post_delete, nor does it state when not to use this tool, so it stops short of a 5.

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