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

Annotations only cover the safety profile (readOnly=false, openWorld=true, destructive=false). The description adds material context: dual-channel publication (web + email), that sent email is irreversible, the per-call confirmation toggle, and the Cotlet API key requirement. That is real behavioral value beyond the annotations.

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?

Front-loaded with the key action. Slightly redundant ('Publish a draft now' / 'Publishes a draft immediately') and confirmation is stated twice, but every remaining clause carries information.

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?

With only two params, no output schema, and low complexity, the description covers action, side effects, confirmation, and auth adequately. Naming the schedule_post alternative would make it fully complete.

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 baseline is 3. The description elaborates on send_email ('unless send_email is false, by email to your subscribers') and reinforces post_id provenance ('draft'), plus the irreversibility note that gives send_email real weight.

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?

Specific verb + resource (publish a draft) with the 'now' qualifier that distinguishes it from substack_schedule_post and substack_create_draft. An agent can route to it without opening the 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?

The 'now' framing implicitly contrasts with scheduling and the description states the confirmation expectation ('confirm with the user before each call'). It never names the alternative tool explicitly (schedule_post), so it falls just short of explicit when/when-not routing.

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