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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds real value beyond that by disclosing the cost ('FREE') and clarifying that output is share URLs / copy-and-open targets, not actual posts — but says nothing about auth needs or per-platform limitations.

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?

A single front-loaded sentence; the 'FREE' tag and verb come first. The long platform enumeration is verbose but earns its place by telling the agent exactly which networks are covered.

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?

With a nested-object parameter at 0% schema coverage and no output schema, the description needs to explain variant structure and return shape but does neither. Annotations cover the read-only safety profile, but an agent still cannot construct a valid call from this text.

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 0% with three parameters including a nested 'variants' object. The description only alludes to 'each variant' and never explains what key 'link' or 'mediaUrl' should hold or what shape a variant takes, so it fails to compensate for the undocumented schema.

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?

States a specific verb+resource ('builds official one-tap share URLs') and enumerates the platforms covered plus the copy-and-open fallbacks. An agent can distinguish this URL-generation tool from omnipost_publish without opening the schema, though no sibling is named explicitly.

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 never states when to use this instead of omnipost_publish or omnipost_fanout, only what it produces. 'FREE' hints at cost-based selection but no explicit when/when-not guidance is given.

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