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

Annotations already declare the safety profile (idempotentHint=true, destructiveHint=false, openWorldHint=true), so the bar is lower. The description adds useful plan-tier context ('Studio and up') and implies a persistent ongoing subscription rather than a one-off action, but says nothing about failure modes for lower tiers or how a follow is later removed.

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, front-loaded with the core action and scope, with no filler. The 'Studio and up.' fragment is terse but functional.

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 mutation tool with no output schema, the description covers purpose, tier requirement, and the behavioral distinction from watching a name. It omits the filer identifier format and any lifecycle detail (how to stop following), which an agent would still need.

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 0% and the single 'filer' parameter is completely undocumented in the schema, so the description carries the full burden. 'Follow an adversary' clarifies that the value is an entity/person rather than a filing, but never specifies the expected format (name, CIK, or internal ID), leaving the agent guessing what to pass.

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 ('Follow an adversary — every filing they make, anywhere'), which is clearly distinct from one-shot lookups like filer_activity. It also contrasts itself against the 'watching a name' concept, though it does not name the sibling tool (e.g. watch_mark) 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?

Gives a clear selection rationale — use this to catch what a filer does NEXT rather than tracking a name — plus an eligibility prerequisite ('Studio and up'). It stops short of naming the alternative tool or stating when-not to use it.

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