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

Goes well beyond the annotations by disclosing content_rules validation, the 422 + no-schedule outcome under enforce:block, and a re-check immediately before publishing. It does not address the idempotentHint=false risk (e.g., duplicate schedules) or explain what 'existing text' refers to, leaving some behavioral gaps for a destructive, open-world mutation.

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 dense sentences, front-loaded with the primary action and time-selection logic, with validation caveats after. Some clauses (parenthetical mutual exclusion, re-check timing) are compressed almost to the point of ambiguity, but nothing is wasted.

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 5-parameter mutation with no output schema, the description covers the scheduling mode, validation failure behavior, and character limit, which is most of what an agent needs before calling. Still missing what the call returns (schedule identifier) and how to inspect or cancel the resulting schedule, and the destructiveHint=true framing is never explained.

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 two facts the schema lacks: the 500-character cap on text and the mutual exclusivity rule linking publish_at and auto_optimize_time. It omits the deprecated schedule_at alias, though the schema already flags that.

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 ('Schedules an existing text') and bounds scope with the character limit and the two time-selection modes. It does not distinguish itself from close siblings such as publish or list_schedules, so an agent must still infer which scheduling entry point applies, but the core purpose is unambiguous.

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 closing sentence explicitly scopes applicability: 'text-only posts with a specific time or when the user wants the system to pick the time,' and the mutual exclusivity of publish_at vs auto_optimize_time is spelled out. There is no explicit when-not or named alternative tool, which keeps it short of a 5.

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