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

No annotations are provided, so the description carries the full burden. It mentions 'Max - 12 Billing per call: 1 Credits' which is a rate/billing constraint, and that is useful. However, it does not disclose whether this is a read-only operation, whether it returns paginated data, or any side effects. It also does not explain behavior like CORS bypassing, which is mentioned in the schema but not in the description. The description adds minimal contextual behavior beyond 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?

The description is extremely short, essentially a single sentence plus billing note. It is concise but arguably under-specified. The billing information is arguably redundant or could be placed elsewhere. It is front-loaded but lacks structure like sections or clear separation of purpose vs. usage. It earns a 3 because it is short and to the point, but it misses opportunities to add valuable guidance without being verbose.

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?

Given the tool has 4 parameters, no output schema, and no annotations, the description is insufficient for an agent to understand what the tool does, how to use it, and what to expect. Key missing information: what 'media comments users' actually returns (list of users? comments with user info?), how pagination works, whether shortcode is required, and any limitations. The description is too minimal for a data retrieval tool of moderate complexity. It addresses billing but not functional completeness.

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?

The schema description coverage is 100%, so the description does not need to add much. However, the description provides no additional context for parameters (e.g., that 'shortcode' is the media identifier, or how 'end_cursor' is used for pagination). The schema already defines each parameter, but the description adds nothing beyond that. Since coverage is 100%, baseline 3 is appropriate; the description does not hinder parameter understanding but adds no extra value.

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 'Get instagram media comments users' is somewhat vague: it specifies 'Get' and 'comments', but the phrase 'media comments users' is awkward and unclear. It does not clearly distinguish from siblings like get_likes or get_post_info, though 'comments' is a specific resource. It is more than a tautology but lacks a clear statement of what the tool returns (e.g., a list of commenters or comments with users).

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 explicit guidance on when to use this tool versus alternatives. No mention of prerequisites like needing a shortcode, which is a required parameter in practice (though not marked required). No mention of pagination usage or when to use 'sort' options. The description provides no context for selection.

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