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

The description says "List comments," which asserts a read-only retrieval operation, while the annotations declare readOnlyHint=false (i.e., the tool may modify its environment). That is a direct contradiction in the read/write dimension, and the description adds no other behavioral context (rate limits, auth, pagination behavior).

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?

It is a single front-loaded sentence with zero filler, so nothing wastes the agent's attention. The flip side is that at one clause it is arguably under-specified for a tool with cursor pagination, keeping it just below a 5.

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 three-parameter listing tool with no output schema this is minimally adequate: the schema covers all inputs and there are no return values to explain. However, it omits any note on pagination flow (reuse cursor, omit on first call) or that only public content is supported, which the annotations' contradictory readOnlyHint makes more consequential.

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 url, limit, and cursor are all documented in the schema itself (public URL, max items with "collection can return fewer," opaque cursor). The description adds no meaning beyond that, which is the expected baseline when the schema does the heavy lifting.

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 verb and resource ("List comments") and scopes it to a Facebook post or video, which separates it from the instagram_comments sibling by platform and by target object. It is clear but never explicitly contrasts itself with the other *_comments / stats tools in the sibling set, so it stops 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?

There is no guidance on when to use this tool versus instagram_comments, instagram_stats, or the other siblings, and no mention of prerequisites such as the post being public. The only usage signal is the implicit platform/object scoping in the single sentence, which the agent must infer.

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