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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so safety is covered. The description adds genuinely useful context beyond the annotations: it requires an API key and consumes the plan's request quota, which affects call budgeting. It stops short of describing error or pagination behavior, but for a single-value read that is a minor gap.

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 short sentences with no filler; the core action and the returned values are front-loaded, with the operational caveat (API key, quota) placed after. Every clause earns its 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?

For a one-parameter read tool whose annotations carry the full safety profile, the description covers the action, the cardinally relevant return fields, and quota cost. With no output schema, a little more detail on the returned shape (e.g. boolean follow flag vs counts) would close the remaining gap.

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% and the single user_id parameter is fully documented in the schema as the profile UUID. The description only restates that the UUID identifies the profile, adding no format or constraint detail beyond the schema. Baseline 3 applies.

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 and resource ('Get follow status') and adds the returned data ('follower count'), which goes beyond the tool name. It does not explicitly distinguish itself from any sibling, but no sibling overlaps this function, so the lack of differentiation is low-risk.

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?

Usage is implied by the name and the required profile UUID, so an agent can infer when to call it. However, there is no explicit when-to-use guidance or stated exclusions relative to siblings such as get_profile, which also returns profile-level information.

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