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

Annotations already declare readOnlyHint=true, idempotentHint=true and destructiveHint=false, so the safety profile is covered. The description adds one genuinely useful behavioral fact beyond that — results are filtered to catalog-available channels, so some watched content will be absent — but says nothing about result volume, ordering, or how history is populated (record_watch is the likely sibling).

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 brief sentences with no filler, and the scoping constraint is front-loaded. It is efficient, though the title and description restate each other somewhat and the description could carry more without becoming bloated.

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 paginated read tool with full annotation coverage and complete schema descriptions, this is minimally adequate. However, with 41 siblings including several history-related tools and no output schema, the description never states the return shape, ordering, or how to distinguish watch history from chat history.

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%: both limit and offset are documented, including the silent cap at 50 and the next_offset pagination hint. The description adds no parameter meaning beyond that, so the 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?

Names the resource precisely (history of channels watched by the owner) and adds a scope constraint (only channels available in the catalog), which separates it from chat_history and clear_history by content. The verb is implied rather than stated (returns/lists), so it falls just short of a 5.

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?

No indication of when to call this versus the numerous sibling history tools (chat_history, clear_history, record_watch, forget_watch) or what triggers it. The catalog-only filter hints at behavior but is not framed as usage guidance.

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