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

Annotations already declare destructiveHint=true, openWorldHint=true, and non-idempotent, so the safety profile is covered; the description adds genuinely new behavior: each output item carries a previewUrl, and validation failures return output.errors with a documented retry path. It does not explain why the operation is flagged destructive (immediate 'now' publishing is irreversible) or disclose any rate limits, so it stops short of full disclosure.

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?

Purpose and the negative constraint are front-loaded, and the two examples earn their space by resolving an ambiguous cardinality rule. The formatting is a bit list-heavy for a description of this length, but there is no filler sentence.

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 deeply nested, multi-object creation tool, the description supplies the usage trigger, the exclusion, the dependency on integrationSchema, the return-value cues (previewUrl, output.errors), and the retry path. With an output schema and full annotation coverage present, nothing an agent needs to call it correctly is missing.

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%, so baseline is 3, and the two worked examples add real meaning the schema does not convey: the cardinality relationship between socialPost and postsAndComments (N posts vs. one post plus comments). The array-length descriptions are slightly indirect and the 'first item is the post' note repeats the schema rather than extending it.

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 and resource ('create a draft, scheduled, or immediate social media post on their connected channels') and names the schema tool it depends on. It also explicitly carves out what it is not ('Do not use this to update or delete existing posts'), which separates it from deletePostTool and other post-management siblings.

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 opening clause gives an explicit trigger condition ('Use this when the user wants to create...'), the closing lines give an explicit exclusion ('Do not use this to update or delete existing posts'), and it points at integrationSchema as the prerequisite for building settings. When/how-not/alternative are all present.

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