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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and closed-world, so the safety profile is covered; the description's "Does not change anything" reinforces it cheaply. It adds real behavioral value by disclosing the required guideVersion handoff to save_post, but says nothing about what happens on an unsupported surface (the schema's "Ad channels have no guide" is the only hint).

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?

Purpose is front-loaded, then contents, then the workflow imperative, then exclusions and related tools — a sensible order. The opening sentence is a very long parenthetical-heavy list, which is dense but each element helps an agent decide whether the guide covers its need.

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?

Output schema exists, so return values needn't be explained; the description instead covers scope, workflow, exclusions, and sibling routing. With full schema coverage and rich annotations, an agent has everything needed to select and invoke this correctly.

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 coverage is 100% so the baseline is 3, but the description adds value by naming surface values not in the schema: blog, faq, competitor_page, instagram, tiktok, youtube, pinterest, plus the conditional content variations per surface. It still doesn't state casing/format constraints on the surface string.

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?

Opens with a specific verb+resource ("Returns the drafting guide for one channel") and then enumerates the guide's contents, so an agent knows exactly what comes back. It also explicitly distinguishes itself from get_brand_context ("Claims and sources are not in the guide") and lists related siblings.

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 an explicit workflow: "Check a draft against it before saving, then pass its guideVersion to save_post." It also states what the tool is not for and routes the agent to get_brand_context for claims/sources, so both the when and the when-not are covered.

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