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

With no annotations and no output schema, the description carries the disclosure burden and does state the return format ('full markdown text') and that it operates on exactly one post. It omits error behavior for an invalid slug and any note on large-post/truncation handling, which keeps it 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?

A single sentence, front-loaded with the action and resource; the parenthetical sourcing hint is compact and earns its place. No 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 tool with no output schema, the description covers identity, scope, return format, and slug sourcing. Minor missing items are invalid-slug behavior and how content is returned when very large.

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% and the schema already documents 'slug' with a concrete example. The description only restates 'by slug' and adds a sourcing hint, so a baseline 3 is appropriate when the schema does the parameter work.

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?

Specific verb ('Read') plus resource ('full markdown text of one blog post') with scope ('by slug'), and it names the sibling list_posts as the source of slugs. An agent can distinguish it from list_posts and search_posts without opening any 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?

It gives a clear prerequisite/workflow hint ('get slugs from list_posts'), which tells the agent when to reach for this tool. It does not explicitly contrast with search_posts or state when not to use it, but usage is clear for a single-entity reader.

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