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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false, covering safety and idempotency. The description adds valuable behavioral context: pagination details (200 entries per page, has_next_page, next_cursor) and the conceptual rationale for using followings over followers. It does not contradict annotations.

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 four sentences, each earning its place: purpose, pagination, use-case rationale, and alternatives. It front-loads the core function and keeps the alternative routing at the end, with zero redundancy.

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 present and annotations covering the tool's safety profile, the description needn't detail every return field. It covers the main use case, pagination, and alternative tools. Missing details like error handling or rate limits are minor given the existing structured context.

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%, so the schema already documents all three parameters. The description adds minor context like '@handle' and '200 entries per page', which reinforces the schema but does not significantly go beyond it. Baseline 3 is appropriate.

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 a specific verb ('List') and resource ('accounts a given X user follows'), with clear identification via '@handle'. It also explicitly distinguishes itself from sibling tools (followers and check relationship), making the tool's purpose unambiguous.

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?

It explicitly explains when to use this tool ('infer a user's interests, information sources, or professional network') and contrasts it with followers ('who someone follows is usually a stronger signal of intent'). It also points to the alternative for testing a single pair, giving clear routing guidance.

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