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

No annotations exist, so the description carries full responsibility for behavioral disclosure. It only states 'Retrieves the reels' with no mention of authentication requirements, rate limits, output format, or potential errors, which is minimal for a retrieval tool.

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 a single, front-loaded sentence conveying the core purpose, followed by two brief metadata lines (group and billing). There is no unnecessary verbosity or redundancy.

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 tool with one parameter and no output schema, the description is adequate but lacks details about what exactly is returned (e.g., reel IDs, metadata) and any prerequisites. Given the lack of annotations, a bit more context would improve 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 input schema already provides a full description and example for the 'url' parameter (100% coverage). The tool description adds no additional semantic meaning beyond what is already in the schema, aligning with the baseline for high schema coverage.

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 retrieves 'reels from a given Facebook profile URL' with a specific verb and resource. It distinguishes from sibling tools like get_facebook_v3_profile_about and get_facebook_v3_profile_photos which target different content types.

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?

Usage context is implied by the name and description – it is for fetching reels from a Facebook profile. However, there is no explicit guidance on when to use this tool versus siblings or when not to use it (e.g., public profiles only).

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