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

Annotations already declare idempotentHint and destructiveHint, and the description usefully adds specifics: validation of content, media and quota occurs before scheduling, and idempotency is scoped precisely to 'same post and timestamp.' It does not explain what the destructiveHint actually affects (e.g., replacing an existing scheduled time), leaving one gap against the annotation.

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, each carrying distinct information (action, timestamp constraint, validation, idempotency), with the core purpose front-loaded. No filler or restated title.

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?

An output schema exists, so return values need not be described, and the description adequately covers validation behavior, timestamp format and idempotency for a two-parameter tool. The only missing piece is the meaning/required state of post_id, which is an ambiguity an agent would need resolved.

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 only 50%: scheduled_at is documented in the schema, but post_id has no description anywhere. The description reinforces the timestamp constraint ('must contain Z or an explicit timezone offset'), which duplicates the schema text rather than adding new meaning, and says nothing about what post_id must reference. Baseline 3 for partial coverage.

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 (schedules) and resource (post) with a clear scope modifier: 'for future public publication,' which implicitly separates it from publish_post and create_post. It does not name a sibling outright, but the temporal framing makes the distinction readable without opening schemas.

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?

Usage is implied by 'for future public publication' – an agent can infer this is for deferred publishing rather than immediate publish_post. However, there is no explicit when-to-use statement, no prerequisites (e.g., does the post need to exist as a draft first?), and no named alternatives.

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