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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds semantic context about how similarity is determined but says nothing about ordering, whether fewer than `limit` results may return, or other behavioral traits beyond the 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?

A single sentence with zero filler; the core concept (similar channels by category and audience) is front-loaded, and the trailing clause adds the purpose rather than repeating the name.

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 simple read-only lookup with only two parameters and an output schema that already defines the return shape, the description is largely sufficient. The only material gap is that it never hints at result ordering or the effect of `limit`, which matters mildly for a ranked-list tool.

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 coverage is 50%: `channel` is well documented in the schema as a slug or numeric id, while `limit` carries self-describing default/min/max constraints. The description adds no parameter meaning of its own, so the baseline 3 is appropriate rather than earned.

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 names the resource (channels resembling a given one) and the similarity basis (category and audience), which is more specific than the bare title 'Similar channels'. It does not, however, differentiate itself from siblings like search_channels or get_channels, so an agent must infer which discovery tool applies.

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?

The clause 'the peer cohort to compare a channel's metrics against' implies the use case (benchmarking a channel against peers), which is real but indirect guidance. There is no explicit when-to-use, when-not-to-use, or named alternative versus search_channels.

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