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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, covering safety. The description adds the billing cost ($0.006 per request), which is useful behavioral context. However, it doesn't disclose other traits like rate limits or pagination (though single-request). With annotations covering safety, a 3 is appropriate.

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 three short sentences, front-loading the core action and then listing returns and cost. Every sentence adds value with no waste.

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 there's no output schema, the description partially fulfills the need by listing return fields (full text, engagement metrics, author info, metadata). However, for a data-fetching tool, it could be more complete by mentioning response format, error cases, or rate limits. Annotations and full schema coverage reduce the burden, but the description leaves some gaps.

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 the schema fully documents both parameters (tweet_id and get_sentiment). The description doesn't add any parameter details beyond the schema, so baseline 3 is correct.

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 it retrieves a single tweet by numeric ID and lists the return contents (full text, engagement metrics, author info, metadata). It doesn't explicitly distinguish itself from sibling tools like twitter_tweet_comments or twitter_tweet_quotes, but the focus on a single tweet's details is clear from the name and description.

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 implies usage (get one tweet by ID) but provides no explicit guidance on when to use this versus alternatives such as search_twitter or other tweet-related endpoints. It hints at precision (numeric ID) but lacks conditions or exclusions.

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