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

readOnlyHint=true already establishes this is a safe read, and the description usefully adds that the response is the post's *full* content keyed by a unique slug rather than a list or snippet. It says nothing about behavior on a missing/unknown slug, error handling, or any response shape nuance.

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?

A single front-loaded sentence with the resource, scope, and lookup key; zero filler.

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 one-parameter read with readOnlyHint and no output schema, the definition covers the essentials: what is returned, the domain, and the key. Only the failure case (nonexistent slug) is left unaddressed.

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 0% and the description only echoes 'by slug' with no format, example, or hint on where the slug comes from (URL segment, search results). It does not compensate for the undocumented parameter.

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 (fetch) and resource (blog post's full content) qualified by the lookup key (slug), so it is clearly distinguishable from a list-style sibling like search_blog_posts. It stops short of explicitly naming that sibling to route the agent.

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 only implied: the agent must already know it needs a slug and wants full post content. There is no explicit when-to-use/when-not guidance, nor any pointer to search_blog_posts for discovering a slug in the first place.

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