Post a text activity

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

Annotations already signal that this is a write, non-idempotent, non-destructive operation. The description adds the login requirement (`[Requires login]`) and clarifies the dual create/update behavior, which is useful context beyond the annotations. No contradictions noted.

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 just two sentences, with the login requirement front-loaded and the core behavior stated efficiently. Every word earns its place with no redundancy.

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 low-complexity tool with two parameters and an output schema, the description covers the essential context: what it does, who it affects, and the create/update distinction. No significant information gaps.

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 parameters `id` and `text` are already well documented. The tool description only reiterates the `id` semantics for updates, adding no new meaning beyond the schema.

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 clearly states the tool's action ('Post a new text-status update') and resource ('authenticated user's own AniList profile'), and explicitly mentions the update variant via an existing `id`. This distinguishes it from sibling tools like `post_message_activity` and `delete_activity`.

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 indicates that the tool is for the authenticated user's own profile and can either create a new post or update an existing one by passing an `id`. While it doesn't explicitly name alternative tools, the context is clear enough, and the sibling list includes `post_message_activity` for a different activity type.

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