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

Annotations already declare readOnlyHint and openWorldHint, and the description adds real context beyond them: ordering, the exact fields returned, the deliberate exclusion of counts, and the 1-credit cost. Pagination and rate/limit behavior remain undisclosed.

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 opening repeats the title verbatim before restating the same idea with added detail ('Accounts a user follows, most recent first'), which is wasted front-load. The remaining sentences (counts exclusion, credit cost) earn their place.

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 no output schema, the description usefully enumerates the returned fields and the credit cost. However, for a 4-parameter paginated list tool it omits how limit/cursor interact and what cache_max_age does, leaving an agent unable to page or tune results confidently.

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 coverage is 50%: cursor and handle are documented in the schema, but limit (default 20) and cache_max_age have no description anywhere, and the description says nothing about any parameter. It fails to compensate for the uncovered half of the schema.

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?

States a specific verb+resource: lists the accounts a given user follows, plus ordering (most recent first) and returned fields. It never names the adjacent sibling mixcloud_followers, so an agent must infer that the reverse relationship is a different tool.

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?

Provides one useful routing rule — counts aren't in this list, fetch a profile for them — which points at mixcloud_profile. There is no guidance on when to use this versus mixcloud_followers, and no stated prerequisites for the handle.

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