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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered structurally; 'Free, read only' largely restates that. What the description genuinely adds is the 7-day recency window on the recent bucket and the set of returned fields. It says nothing about ordering, volume, or pagination, so it goes modestly beyond annotations rather than richly.

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 sentences, front-loaded with the scope and the upcoming/recent split, then the usage triggers, then the safety and sibling pointer. Every clause carries information; nothing is padding.

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 compensates by enumerating the returned fields (video, channel, time, link) and the two result categories. For a zero-parameter read tool that is everything an agent needs to call it and interpret the result.

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?

The tool takes no parameters, so there is no parameter meaning to add and the baseline of 4 applies. The description is correct not to invent filtering options that the empty schema does not support.

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?

The description names the resource (scheduled posts across the user's videos) and splits it into two concrete buckets, 'upcoming' (scheduled or waiting for export) and 'recent' (went out or failed in the last 7 days). It also lists what each record carries (video, channel, time, link), which lets an agent separate it from list_my_videos or prepare_post without opening any 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?

Two explicit trigger conditions are given: call before scheduling so posts do not collide on the same day, and call when the user asks what is planned. It also routes the undo case to the sibling cancel_post, so the agent knows both when to use this tool and which alternative handles the adjacent need.

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