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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is clear. The description adds useful context: the channel is public, what data is returned, and that the call costs 1 credit. It does not explain caching behavior, rate limits, or error handling.

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 compact and front-loaded: it states the resource, lists returned fields efficiently, and adds the cost note. No sentence 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?

Because there is no output schema, listing the returned fields is important and well done. The description is nearly complete for a simple read-only profile lookup, but leaves the optional cache_max_age parameter entirely unexplained.

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?

The handle parameter is documented well in the schema, but cache_max_age has no description in either the schema or the tool description. With only 50% schema description coverage, the description does not compensate by explaining what cache_max_age controls or how it should be used.

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 that it retrieves a public Twitch channel profile and enumerates the fields returned (followers, partner/affiliate status, bio, avatar, banner, account age, live status). This clearly distinguishes it from content-focused siblings like twitch_userVideos or twitch_clip, though it lacks an explicit verb and does not name alternatives.

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?

There is no explicit guidance on when to use this tool versus alternatives such as twitch_userVideos, twitch_userSchedule, or twitch_clip. Usage is only implied by the tool name and field list.

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