Get User Reels

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

Annotations already declare readOnlyHint true, so the safety profile is covered. The description adds valuable behavioral context by explaining it fetches from the grid page and avoids N+1 rate limiting, plus details the return structure. However, it doesn't disclose potential limitations like pagination or errors, but the annotations and output schema mitigate some of that.

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 well-structured with clear 'Args' and 'Returns' sections, and every sentence provides useful information. It is slightly verbose, especially the 'ctx' line and the detailed return list, but overall it is efficient and scannable. The front-loaded purpose statement is strong.

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's moderate complexity, the description is complete: it covers purpose, parameter semantics, return format, and usage guidance relative to siblings. The presence of an output schema further reduces the need to describe return values, and the description supplements this with a concise summary of the returned dict.

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 0%, so the description carries the burden. It clearly explains username with examples and max_reels with its default value. However, it lists 'ctx' as an argument that is not present in the input schema, which could confuse an agent into thinking it's a user-supplied parameter. This is a minor inconsistency preventing a perfect score.

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 clearly states the tool's purpose with a specific verb and resource: 'Get an Instagram user's reels with structured data.' It also distinguishes itself from siblings by specifying it returns data from the grid page without navigating to individual reels, and mentions using get_post_details for full engagement data.

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?

The description provides clear context for when to use this tool vs alternatives: it explicitly recommends using get_post_details for full engagement data on individual reel URLs. It also highlights the benefit of avoiding N+1 rate limiting by not navigating to each reel, implying it should be used for efficient bulk listing.

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