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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint, but the description adds meaningful behavioral context: the credit cost per profile and the possibility of a 403 for restricted account tiers. This covers authorization and cost behavior not present in annotations. It does not mention pagination details, but those are partially covered by the cursor parameter description in the schema.

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 brief, starting with the core purpose ('Accounts that retweeted a tweet') then adding cost and error context. Each sentence adds distinct information and no words are wasted. Though the first sentence is a fragment, it is immediately informative.

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 description covers cost and tier access, but lacks details on response format, pagination, and parameter semantics for id and count. With no output schema, an agent needs more context about what data is returned for each retweeter. The cursor description in schema helps with pagination, but overall the description is only partially complete for a non-trivial list endpoint.

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 input schema describes fresh and cursor, but id and count lack descriptions. The tool description does not explain that id refers to the tweet ID or that count limits the number of retweeters returned; it only implies the tweet context. With schema coverage at 50%, the description fails to compensate for the undocumented parameters.

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 the resource as 'Accounts that retweeted a tweet,' clearly indicating the tool retrieves retweeters for a given tweet. It distinguishes this from siblings like get_quotes and get_replies by the specific resource, though it does not explicitly name alternatives. The verb is implied by the tool name, so it meets the clarity bar.

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 gives no guidance on when to use this tool over its siblings such as get_quotes or get_replies. It only provides cost and tier restrictions ('0.5 credit per profile. Not every account tier can read this; a 403 is free.'), which are operational notes, not usage selection criteria. No alternative tools are mentioned.

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