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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior, so the bar is low. The description adds genuine behavioral context beyond that: it discloses that reach is measured in meetups, and that drafts live in "their Stream," which tells the agent how to interpret returned values.

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 sentences, front-loaded with the resource and followed by the routing hint. The first sentence is a dense field list, but every element is decision-relevant rather than padding; it is appropriately sized, if slightly heavy.

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 zero-parameter, read-only list tool with an output schema and full annotation coverage, this description is more than sufficient. Since the output schema already defines the return shape, describing the fields is a bonus rather than a necessity, and nothing an agent needs to invoke it correctly is missing.

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?

There are zero parameters, so the schema carries nothing to explain and the baseline is 4. The description correctly introduces no parameter syntax, matching a no-arg list tool.

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 resource (the person's own Hunchful channels) with an explicit ownership qualifier (they are the owner, one owner today), which distinguishes it from sibling channel tools. It enumerates the returned fields (audience, live/paused, followers, reach, events ahead, scheduled posts, drafts), so an agent knows exactly what this tool yields.

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?

"Use it first to find a channelId for the other channel tools" gives explicit routing guidance and positions this tool ahead of downstream channel tools. It stops short of naming a specific alternative or stating when this tool is NOT the right call, but the context is clear.

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