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

With no annotations, the description carries the full burden. It does disclose that only published posts are returned and that the output is markdown, which is useful. However, it omits any behavior around missing slugs, locale handling, or whether other metadata is included. It is minimally transparent but not rich.

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 a single, brief phrase that gets straight to the point with no wasted words. It is front-loaded and appropriately sized for a simple read operation, though it is a fragment and could be a full sentence.

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?

For a low-complexity tool with full schema coverage and no output schema, the description explains the core return value ('full body... as markdown') and the scope ('one published'). It does not discuss errors or edge cases, but the tool is simple enough that this is adequate. Slightly more detail on error behavior would be needed for a 5.

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 baseline is 3. The description adds nothing about the parameters beyond what the schema already provides; it does not explain the slug semantics or locale defaults, but the schema already does. The description earns no extra credit.

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 title 'Read a blog post' provides the verb, and the description specifies the exact resource: 'the full body of one published blog post, as markdown.' It clearly differentiates from siblings like list_blog_posts by indicating a single post, and from generic fetch by specifying the format and published status.

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?

Usage is implied: if you need one post's content, use this tool. The slug parameter description in the schema ('From a list_blog_posts result') hints at a two-step flow, but the description itself does not explicitly state when to use this vs list_blog_posts or search, nor does it mention exclusions.

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