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

Adds substantial context beyond the annotations: nothing is published, nobody is reached, the draft becomes a card in the person's Stream and opens Studio's composer, and imageUrl is handed back rather than fetched. This is exactly the side-effect detail an agent needs for a write tool whose annotations only say non-destructive/non-read-only.

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 core action and consequence, and most sentences carry real constraints. It is dense but slightly repetitive — the 1000-character cap and the 'handed back, never fetched' imageUrl behavior are each stated in both the description and the schema.

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 an output schema present, return values need not be explained, and the description covers side effects, constraints, voice guidance, and the schedule_post hand-off. Nothing material for correct invocation is missing.

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 text/title/channel/imageUrl, including the 1000-character limit, the optional title, and channel-by-id/@name/name fallback. The description restates the character cap and imageUrl behavior rather than adding format or edge-case detail beyond the schema, so the baseline 3 is appropriate.

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+resource (write a post draft) and its scope precisely — words plus optional title, for one of the person's channels. It cleanly separates itself from siblings like create_post (immediate publishing) and schedule_post by stating nothing is published and the draft lands in the Stream/Studio composer.

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?

"Use it when the person asks you to draft a post" gives an explicit trigger, and it names schedule_post as the follow-up for timing. It also sets voice/accuracy constraints (write in their voice, never invent people, numbers or quotes). It stops short of explicitly routing the agent away from create_post for immediate publishing, so 4 rather than 5.

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