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

Annotations cover the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true). The description adds real context beyond them: scheduled vs immediate publishing, that large images may take a while and can time out around a minute, that the post is attributed to the admin account and visible to channel members, and that a Cotlet API key with app access is required.

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 purpose, but the first two sentences state the same thing twice ('now or at a set time' / 'now or scheduled') and the confirmation instruction is split across two sentences. Some trimming would tighten it, though nothing is fatally bloated.

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 write tool with no output schema, the description covers the essentials an agent needs: timing semantics, visibility to members, timeout risk on images, auth requirement, and confirmation behavior. Return format is unstated, but that is minor for a post-creation action.

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%, so the schema already documents all four parameters. The description only reinforces publish_at ('now or at a set time') and image handling ('large images'), adding marginal meaning beyond the structured fields; baseline 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?

States a specific verb and resource ('Post ... in a community channel') plus the two modes (now or scheduled). An agent can tell this is a create/publish action rather than the sibling read tool uscreen_list_community_channels, which the schema even points to for channel_id.

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 clear operational guidance: confirmation is on by default and can be disabled, and because the post 'reaches other people' the user should be confirmed with before each call. It doesn't name alternatives (there are none for creating posts), but it supplies the conditions that matter for safe use.

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