Publish Link Thread

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

Annotations already indicate this is a write operation (readOnlyHint=false) and not destructive or idempotent. The description adds nothing about side effects, required permissions, rate limits, or visibility of the post (e.g., public to followers). It simply states what it does, which is largely evident from the name. No contradiction with annotations, but the description does not enrich behavioral understanding beyond the minimal facts.

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 short and to the point, with the purpose stated in the first sentence and parameters listed in a clear, readable format. It is front-loaded with the core function. However, it omits two parameters, which makes it incomplete but still concise. The structure is effective for quick scanning.

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 has 5 parameters, but the description only mentions 3, leaving reply_control and response_format undocumented both in the description and (partially) in the schema. There is no output schema, so return format is unspecified. The description does not mention any behavioral nuances like authentication requirements, public visibility, or rate limit consumption. For a publish action, this is a significant gap—users need more context on how the post will be presented and what the response contains.

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 covers the three main parameters (threads_user_id, text, link_attachment) but adds limited meaning beyond the schema. It clarifies that 'text' contains the URL and that 'link_attachment' is the URL for the preview, which is slightly redundant with the schema's 'URL for link preview.' It omits the optional reply_control and response_format parameters entirely. Given schema coverage of 60% for these three, the description barely compensates for the missing two. Baseline 3 is appropriate.

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: 'Publishes a thread post with a link attachment.' This specifies the verb (publishes), resource (thread post), and a distinguishing feature (link attachment) that differentiates it from other thread publish tools like threads_publish_text or threads_publish_image. However, it does not explicitly name sibling tools to reinforce the differentiation, so it falls short of a 5.

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?

There is no guidance on when to use this tool versus the other publish variants (text, image, video, carousel, gif). The description does not mention conditions like 'use when you want to include a link preview' or point users to alternative tools for other post types. This leaves selection to inference from the name and description alone.

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