post_photo

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

No annotations are provided, so the description carries the full burden. It only states the action (posting) without disclosing side effects, authentication requirements, rate limits, or whether the post is immediately published. This is insufficient for a write operation, similar to the update_drive example.

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 a single, direct sentence with no fluff or redundancy. It is front-loaded and appropriately sized for a tool with two simple parameters.

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 annotations and no output schema, the description lacks essential context such as prerequisites, post-posting behavior, or error scenarios. It only covers the fundamental action, which is insufficient for an agent to invoke it correctly.

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?

The description repeats the schema's note that the URL must be public but adds no new meaning for image_url. It does not explain the caption parameter at all, and with schema coverage at 50%, the description fails to compensate for the missing documentation.

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 action ('Dang 1 anh len Instagram' - post a photo to Instagram) and the source ('tu URL anh cong khai' - from a public image URL). This distinguishes it from sibling tools like post_reel, post_story_photo, and post_carousel, which target different content types.

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 implies the tool is for single photo posts, but it does not explicitly mention alternatives or when to use this tool versus post_carousel, post_reel, etc. There is no exclusion guidance or specific context, leaving usage to inference.

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