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

The description adds substantial context beyond the annotations: data source (Embedded Post plugin), count formatting with numeric estimates, returned metadata, limitation that reactor identities require login, notFound handling, pricing, payment methods, and that failed calls are not charged.

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?

Despite being dense, the description is front-loaded with what the tool returns and then covers constraints, limitations, and pricing. Every sentence contributes useful information for correct invocation.

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?

The description covers input expectations, output characteristics, failure behavior, cost, and payment details. With an output schema and read-only annotations also present, an agent has everything needed to call the tool correctly.

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%, and the only parameter is already documented in detail in the input schema. The description reinforces the 10-URL limit but does not add syntax or format details beyond what the schema provides.

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 states a specific resource and operation: reaction, comment, and share counts for public Facebook post URLs. It also clarifies that only totals are returned, distinguishing it from tools that fetch full posts or comments.

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 clearly specifies eligible inputs: up to 10 public Facebook post, photo, or video URLs. It also explains what happens for private, deleted, or non-embeddable posts, though it does not explicitly compare itself with sibling tools like social_facebook_posts.

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