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

Annotations already declare destructiveHint=true and idempotentHint=false, so the safety profile is known. The description earns credit by stating a real behavioral side effect that annotations cannot convey — existing scheduled posts in that slot are left in place — plus a user-confirmation requirement. It stops short of describing what happens if the slot doesn't exist or what the response looks like.

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?

Three short sentences ordered by importance: what it does, how to supply values plus the confirmation warning, then the sibling disambiguation. No filler and nothing buried.

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 destructive, non-idempotent mutation with full schema coverage and strong annotations, the description covers the critical agent decisions: value sourcing, user confirmation, and the adjacent-tool boundary. Minor gap only in not stating error behavior for a nonexistent slot, which is not essential to call it correctly.

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%, and the schema already documents weekday formats, HH:MM local_time, and the optional social_set. The description only restates that weekday and local_time should come from get_posting_slots, which adds sourcing context but no meaning beyond the schema; baseline 3 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?

The description opens with a specific verb and resource: 'Remove a repeating posting slot from the weekly calendar.' The word 'repeating' and 'weekly calendar' narrow scope, and the final sentence explicitly separates this from unschedule_post, so an agent can distinguish it from siblings without opening a schema.

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?

It gives both positive guidance (source weekday + local_time from get_posting_slots) and an explicit exclusion with the correct alternative (use unschedule_post for posts already in the slot). It also adds a procedural prerequisite: confirm with the user first.

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