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

Annotations declare readOnlyHint=true and destructiveHint=false, so the tool is safe. The description adds credit cost per tweet and mentions cache bypass via the 'fresh' parameter, which is important behavioral context. However, it does not explain pagination behavior in detail, but the cursor parameter schema covers this somewhat.

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 one concise sentence with no filler, and the key information (newest first, credit cost) is front-loaded. It is clear and to the point.

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?

Given the tool's simplicity and the rich schema (100% coverage), the description adequately covers usage. It lacks explicit pagination details, but the cursor parameter and output schema absence do not require extensive explanation. The credit cost is a complete addition, so a small gap remains.

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%, so each parameter has a description. The description does not add much beyond the schema, but it mentions credit cost and cache bypass, which relates to the 'fresh' parameter, adding value. Baseline is 3, and this slight addition justifies a 4.

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 fetches the latest tweets of a user, sorted newest first, which aligns with the tool name and distinguishes it from siblings like get_user (user profile info) and get_tweets (likely other tweet fetching). The verb 'get' and resource 'user tweets' are specific.

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 mentions the newest-first ordering and credit cost, which provides context for when to use. It does not explicitly state when not to use or name alternative tools, but the sibling list shows many similar tools. However, the tool's purpose is clear enough that an agent can infer when to use it over, say, search_tweets.

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