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

Annotations indicate this is not read-only and not idempotent, which implies a state-changing create operation. The description adds transparency by disclosing the precedence behavior when both content and blocks are passed, noting that blocks renders and content is kept as a fallback. It also reveals that blocks are rendered as styled components and that HTML in blocks is sanitized by default with sandboxing available. However, it doesn't disclose what happens to existing drafts if the same title is used again, or whether there are any rate limits. Given the annotations already cover the non-readonly/non-idempotent nature, the description adds useful behavioral context, but a 4 reflects a lack of clarification on edge cases like duplicate titles.

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?

The description is dense but well-organized: it opens with the core action, immediately explains the two authoring paths, then gives a clear preference rule, and then closes with the precedence behavior. Every sentence carries meaningful guidance. It's long but earns its length given the complexity of the blocks system. The structure also front-loads the most important decision the agent needs to make: blocks vs content.

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?

Despite having 11 parameters and no output schema, the description is exceptionally complete. It covers the two authoring modes, the block schema details, the preference between modes, precedence when both are given, and key constraints on blocks like no nested columns. The only minor gaps are the absence of return-value documentation (compensated by the absence of an output schema) and no explicit mention of whether the created post is immediately published unless status is 'draft' (though the status parameter default covers this). Overall, this is a model of descriptive completeness for a complex create tool.

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 all 11 parameters are already documented in the schema. The description adds deep meaning beyond the schema, especially for the blocks parameter: it explains the rendering behavior (styled components), the block type list (hero, richText, callout, columns, codeCard, imageGrid, quote, embed, cta, divider, html), and specific conditions (e.g., exactly 2 columns, no nested columns, sandboxed HTML). This goes far beyond the schema's generic 'Structured layout blocks' description and significantly helps an agent compose valid and rich blog posts.

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 clearly states 'Create a new blog post' with a specific verb and resource. It also goes further by explaining the two authoring methods (content vs blocks), which distinguishes it from update_blog_post and publish_blog_post. The description is highly informative and removes ambiguity about the tool's primary function.

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?

The description explicitly says 'Prefer `blocks` for rich, magazine-style layouts; use `content` for simple prose.' This provides direct guidance on when to use each authoring style. It also explains the behavior when both are given, which is an important usage differentiator not evident from the schema alone.

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