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 discloses the auth requirement ('Requires login') and the image upload prerequisite, which is genuine behavioral value, but says nothing about permissions, rate limits, or what creation returns.

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?

Three tight sentences with the core action front-loaded, followed by prerequisites and variant semantics. No filler or repetition of 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?

Covers creation, prerequisites, and post variants for a mutation tool with no annotations and no output schema. It never indicates what is returned (e.g. post id/link), which is the main remaining 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 description coverage is already 100%, so baseline is 3. The description goes beyond it by explaining the semantic relationship between params and post type (url => link post, body => text post, uploaded url => image post), which the flat schema does not convey.

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 (Create) and resource (new post) on a named platform, and enumerates the three post variants (link, text, image). An agent can immediately distinguish this from siblings like create_comment or upload_image.

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?

Explicitly routes the agent to list_communities for valid community values and to upload_image before image posts, which is clear workflow guidance. It lacks explicit when-not-to-use exclusions, but the prerequisite ordering is well covered.

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