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

With no annotations, the description carries full burden for disclosing behavior. It mentions billing (1 Credit per call) but does not state whether it is read-only, any side effects, error handling, or return format. This is insufficient for a tool with no annotation coverage.

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 efficient, using three short sentences that front-load the primary purpose and include only essential metadata (group, billing). No redundant or vague wording, earning a high score for conciseness.

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 tool is simple, but the description is minimal. It lacks any explanation of the return payload, error conditions, or typical use cases. Since there is no output schema, the description should provide more context about what the agent can expect, which is missing here.

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%, with both url and renderableFormats well described in the schema. The tool description adds no parameter-specific information beyond what the schema provides, so a baseline score of 3 is appropriate.

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 media and metadata for a Facebook post URL, using a specific verb and resource. It distinguishes from sibling tools that focus on profiles, photos, or reels by specifying 'post details' and the 'Facebook-Posts' group.

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 implies usage for getting details of a specific Facebook post but does not explicitly state when to use it versus alternatives. No exclusions or alternative tool references are provided, leaving usage context inferred from the tool name and description.

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