threads_create_post

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

No annotations are present, so the description carries full responsibility. It discloses that the tool creates and publishes a post, but does not mention authentication requirements, failure conditions, or the public visibility of the post. These are relevant behavioral aspects for a mutation tool.

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 concise, front-loaded with the main purpose, and lists parameters compactly. The inclusion of 'ctx: FastMCP request context' is unnecessary for an agent but does not significantly hurt the overall clarity.

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?

The tool is simple and the description covers its core purpose and parameters. However, it omits prerequisites like authentication or account linking, and does not mention error handling. The presence of an output schema reduces the need to explain return values, but the description could still be more complete.

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?

Even though schema description coverage is 0%, the description fully explains both parameters: text is defined as 'text content of the post' and reply_control lists all allowed values (EVERYONE, ACCOUNTS_YOU_FOLLOW, MENTIONED_ONLY). This provides complete semantic clarity.

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 states 'Create and publish a text post to Threads' with a specific verb, resource, and medium, clearly distinguishing it from sibling tools that create image or video posts. This gives an unambiguous purpose.

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 explicitly identifies this tool as for text posts, and sibling names make alternative purposes apparent. However, it does not explicitly state when not to use this tool or provide direct comparisons with alternatives.

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