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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive), so the bar is lower. The description adds genuinely non-obvious behavior: it never collects automatically, and its output may carry partial coverage tied to an asOf timestamp. That is useful context an agent cannot get from the annotations or 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?

Three terse sentences, front-loaded with the core action and resource. The middle sentence reads as an instruction to the caller ('State its asOf...') which is slightly cryptic, but nothing is wasted.

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 an output schema covering return values and annotations covering safety, the description only needs to add operational context. It does add the no-auto-collection and partial-coverage facts, but it leaves the sibling-routing and any authentication/access prerequisites unstated, which matters for a tool named alongside four related account-data tools.

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 67% – cursor and username are documented in-schema, while limit is not, though its type, default, and min/max bounds are self-evident in the schema. The phrase 'Read a page' hints at pagination but the description adds no format or constraint detail beyond what the schema already shows.

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: reads a page of the most recent accessible following snapshot or public query cache. It implicitly separates itself from list_followers and query_public_account by specifying 'following' versus followers and by calling out the cached nature, but it never names a sibling explicitly.

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 cached-snapshot framing implies this is for reading existing data rather than triggering collection, but there is no explicit when-to-use, when-not-to-use, or comparison against list_followers, list_tracking, or query_public_account. An agent must infer the choice from the resource name alone.

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