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

Annotations already flag destructiveHint=true, idempotentHint=false, openWorldHint=true, but the description adds non-obvious behavior: the post signature is appended server-side, and a safety gateway can refuse the post for account health, daily limits, or duplicates. It also warns that this queues real content for a real audience, which is meaningful side-effect context beyond the structured hints.

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?

Four tightly written sentences, front-loaded with the core action and scope, then the approval requirement, then the multi-account pattern, then the caveats. No filler; every sentence carries operational value.

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 mutation tool with strong annotations, the description covers the safety profile, approval gate, and refusal conditions well. There is no output schema, however, and the description never says what a successful call returns (e.g., post id, scheduled time, batch id), which leaves a small gap for an agent that needs to chain a follow-up call.

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 the schema already documents all ten parameters in detail (enums, ranges, id lookups). The description reinforces scheduled_at="now" and clarifies the post_batch_id calling pattern, but does not add meaning for media_urls, variant_id, first_comment, tag_ids, or platform_meta beyond what the schema provides. Baseline 3 for high-coverage schema 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?

States a specific verb and resource ('Schedule a post'), pins the scope to ONE connected account, and covers the immediate-publish variant via scheduled_at="now". It also distinguishes the single-account case from the multi-account pattern (call once per account with the same post_batch_id), so an agent can separate it from generic schedule_* 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?

Gives explicit when-to-use (schedule to one account or publish now) and an explicit alternative pattern for a common adjacent need (posting to several accounts → one call per account with a shared post_batch_id). It also states the precondition that the agent must show text/account/time and get explicit user approval before calling.

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