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

Annotations already declare destructiveHint=true and idempotentHint=true. The description adds the precondition that the post must be SCHEDULED, which is useful, but it does not disclose what happens to the prior scheduled time or any state transitions beyond the basic 'changes' verb.

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, efficient sentence that places the core action first and the key constraint ('SCHEDULED post') right after. No filler, repeated information, or unnecessary detail.

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 simple 3-parameter tool with a fully self-describing schema, the description covers the essential distinction from siblings. It doesn't explain return values, but no output schema exists and the tool's outcome is implicit in the action 'changes the future publish time'.

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%, so the parameters are already well-documented in the schema. The description adds no new parameter meaning beyond what the input schema already states about post_id, timezone, and schedule_at.

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 identifies the action (changes), the target (the future publish time), and the scope (a SCHEDULED post). It distinguishes itself from siblings like invoke_schedule_post or invoke_publish_now by focusing on rescheduling an already-scheduled post.

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 phrase 'of a SCHEDULED post' gives clear context that this tool applies only to posts already in the scheduled state. It does not explicitly name alternatives or exclusions, but the precondition is unambiguous enough for an agent to route correctly.

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