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

Annotations already declare destructiveHint=true, idempotentHint=true, and openWorldHint=true, so the safety profile is covered. The description contributes the non-obvious scheduling fallback chain, which materially affects the outcome of a call; it does not restate the destructive/idempotent traits, leaving a minor gap on irreversibility.

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?

Two dense sentences, front-loaded with the core action and state precondition, followed by the scheduling resolution rule. No filler and every clause changes how an agent would invoke it.

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 3-param mutation with full schema coverage and full annotation coverage and no output schema, the description covers the state precondition and the scheduling semantics well. What remains unstated is the effect on publication state beyond scheduling and any revert path, a small gap for a destructive operation.

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 baseline is 3, but the description adds real semantic value for schedule_at by defining the resolution order: explicit schedule_at wins, otherwise an existing schedule is reused, otherwise ASAP. That behavior is not derivable from the schema's terse 'Optional ISO 8601 time' note.

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 ('Approves a PENDING_APPROVAL post') plus the secondary effect ('and schedules it'), which cleanly separates it from siblings like invoke_schedule_post, invoke_publish_now, and invoke_reject_post. The state precondition (PENDING_APPROVAL) further pins down exactly what this operates on.

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 PENDING_APPROVAL precondition gives a clear condition under which this tool applies, which is more than most siblings offer. It stops short of explicitly naming alternatives (e.g., invoke_reject_post for denial, invoke_schedule_post for already-approved posts), so no exclusion guidance is present.

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