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

Annotations already declare readOnlyHint=true and openWorldHint=true, yet the description still adds real value: the API mapping (GET /v1/channels/{channelId}/sources), cursor-based pagination, and the required `read` scope. That auth and pagination context is not derivable from 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?

Three tight sentences, front-loaded with the core purpose followed by pagination and auth details. Every sentence earns its place with no filler.

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 5-param read-only list tool with no output schema, the description covers purpose, filtering, endpoint, pagination, and scope requirement. It omits the shape of returned items, but the mention of cursors makes the call pattern clear enough.

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 type, status, limit, cursor, and channel_id are already documented. The description only restates that type/status are filters and that results are cursor-paginated, adding no syntax or semantic detail beyond the schema. Baseline 3 applies.

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 (list), resource (sources), and scope (in a channel), and even defines what a source is (video/document/website). It does not explicitly name a sibling such as get_source or query_channel, so it falls just short of full sibling differentiation.

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?

Usage is implied by the scope and the optional type/status filters, but there is no explicit when-to-use, when-not-to-use, or routing to alternatives like get_source for a single item or query_channel for content search. Adequate but leaves selection to inference.

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