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

Annotations already cover readOnly, openWorld, idempotent, and non-destructive behavior, so the bar is lower. The description adds useful behavioral context: it returns complete text rather than truncated preview and locates the result under 'article'. This enriches the annotation profile without contradicting it.

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 sentences with zero filler. The core purpose, exact usage condition, return field, and sibling reference are all present and front-loaded. Every sentence contributes value.

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?

With one parameter, a documented output schema, and annotations covering safety, the description is complete. It tells the agent when to use it, what it returns, and how it differs from the nearest sibling. No critical information is missing.

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% for tweet_id, so the schema independently documents the parameter. The description only restates 'by its tweet ID', adding no new format, constraints, or examples beyond the schema. Baseline 3 is appropriate because the schema carries the semantics.

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 a specific action (Get), resource (full body of an X Article), and identifier (tweet ID). It clearly differentiates from get_twitter_tweets by calling out ordinary tweets as a separate case, so an agent can distinguish the tool without opening schemas.

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?

Explicit when-to-use guidance is given: 'when a tweet links to or is an Article and the 280-character preview is not enough.' It also names the alternative for ordinary tweets ('use get_twitter_tweets'), leaving no ambiguity about tool selection.

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