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

Goes well beyond the annotations by disclosing concrete side effects: outbound HTTP requests to each channel platform, writes to the local YAML publish state, and a requirement for valid credentials in the named profile. It also states the exact idempotency key (content.id, channel) and that re-runs return cached state without re-posting, which is far more specific than the generic idempotentHint=true annotation.

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?

Four tight sentences, each earning its place: purpose, side effects, idempotency semantics, and sibling routing. Front-loaded with the action and scope before the caveats.

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?

An output schema exists so return values need no explanation, and the description still covers mutation scope, auth prerequisites, idempotency, and alternatives. Nothing an agent needs to invoke this correctly 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% and the nested objects are richly documented, so the schema carries the parameter burden. The description only points to helper tools (channel_hints, profile_list) rather than adding syntax or format meaning beyond the schema, making the baseline 3 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 (publish), resource (channel variants), and immediacy constraint in the first sentence. The immediacy qualifier distinguishes it cleanly from post_schedule and post_drain without needing 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?

Explicitly routes: use post_publish for immediate-only delivery, post_schedule when any variant needs a future schedule_at, post_drain to flush a built queue. Names the alternatives and the condition that selects each, so no inference is required.

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