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

Annotations already declare the safe read profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower, and the description still adds real behavioral context: it reads a snapshot/cache rather than triggering collection ('Never collects automatically') and warns results may be partial with an asOf timestamp. It stops short of explaining auth requirements or rate limits.

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?

Two compact sentences with the purpose front-loaded, but the phrasing is opaque ('permitted public query cache') and the imperative 'State its asOf and partial coverage' is an odd instruction rather than a clean statement of behavior.

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?

An output schema exists, so return values need not be described, and annotations cover the safety profile. What remains missing is usage routing against siblings and any clarity on the snapshot-versus-cache distinction, leaving the definition adequate but with clear 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 67%, with username and cursor documented in the schema but limit undocumented. The description adds no syntax or format detail for any parameter; 'Read a page' only loosely signals pagination. Baseline 3 applies when the schema carries most of the burden.

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 (Read) and resource (a page of the follower snapshot), so an agent knows this returns followers rather than the following list, accounts, or changes. However, the phrase 'permitted public query cache' muddies what is actually returned and there is no explicit differentiation from siblings like list_following or query_public_account.

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?

No statement of when to use this versus the sibling tools (list_following, query_public_account, list_tracking). The 'Never collects automatically' note hints at a read-only/cache posture but is not framed as a usage condition or exclusion.

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