comments

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds useful behavioral detail beyond that: ordering, inclusion of replies and video titles, and a note about channel tagging. It does not discuss pagination or the meaning of the queue states, whose semantics instead live in the schema.

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 compact sentences, front-loaded with the resource and ordering before the routing hint. No filler, though it spends a sentence on the non-existent 'mine' flag.

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?

An output schema exists, so return values need not be described, and the readOnly annotation covers the safety profile. The remaining gaps are the phantom 'mine' parameter and the absence of any contrast with comment_thread, leaving the agent slightly under-informed about the tool's true surface.

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 100%, so baseline would be 3, but the description asserts a 'mine=true' parameter that does not exist in the input schema. That introduces a phantom flag an agent may try to pass, actively harming invocation accuracy rather than adding meaning. This mismatch pulls the score below the schema-driven baseline.

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 a specific resource (comment threads of channel videos) with ordering (new to old) and payload contents (replies, video title), which is enough to distinguish it from a keyword-stuffed tautology. However it never explicitly contrasts with the close sibling comment_thread, which returns a single thread, so the boundary is left to inference.

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?

It explicitly routes the agent: replying in a thread should be done with the reply tool using the thread_id. It gives a clear context of use (browsing threads from new to old) but offers no when-not guidance or comparison against comment_thread/moderate, so the alternative mapping is only partial.

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