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

Annotations already declare readOnlyHint=true and destructiveHint=false, so safety is covered. The description adds value with an auth requirement (the user's Cotlet API key with access to this app), which is not in the annotations and is exactly the kind of context an agent needs before calling.

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, front-loaded with what is returned then the workflow hint. The field list and the follow-up return sentence overlap slightly ('tiers with access' / 'tiers that can see it'), a minor redundancy rather than filler.

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 no output schema, the description carries the return-value burden and does reasonably well by listing title, body, tiers with access, status and URL. Auth and workflow context are present; only pagination/format edge cases are absent, which is minor for a single-item get.

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 single post_id parameter is documented as 'Post ID from list_posts.' The description adds no parameter-level detail beyond the schema, so the baseline of 3 applies.

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?

Names a specific verb and resource ('Full post', 'Returns one post with its full body and the tiers that can see it') and enumerates the returned fields. It implicitly distinguishes itself from patreon_list_posts by returning a single post, but never names that sibling the way a 5 would.

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?

Gives a concrete prerequisite workflow: 'Use it before update_post to see what is there now.' That is real when-to-use guidance tied to a named sibling. It stops short of explicit when-not-to-use rules or a pointer to list_posts for browsing.

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