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

Annotations already declare readOnlyHint/idempotent/non-destructive, and the description reinforces that with 'Does not change anything.' It adds genuinely new behavioral context: the full inventory of what the guide contains and the guideVersion handoff contract to save_post. It does not cover failure modes beyond the schema's channel note, so it stops short of a 5.

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 purpose, then the content inventory, then the routing rules and exclusions in short declarative sentences. Every sentence carries information an agent needs; 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?

An output schema exists, so return-value documentation is unnecessary, and the description still covers content, usage workflow, the save_post handoff, and the sibling exclusions. Nothing material is missing for correct invocation.

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 there is a single 'surface' parameter, so the schema already carries the meaning, including which channels lack a guide. The description only restates 'one channel' and adds no format or syntax detail beyond that, 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 and resource ('Returns the drafting guide for one channel') and then enumerates exactly what the guide contains (honesty rules, channel craft, writing craft, brand voice, platform limits). It explicitly differentiates itself from get_brand_context, which holds claims and sources, so an agent can pick correctly without opening a 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?

Gives a concrete workflow: 'Check a draft against it before saving, then pass its guideVersion to save_post.' It also names the exclusion — claims and sources live in get_brand_context — and lists related tools, so both when-to-use and when-not-to-use are covered.

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