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

readOnlyHint=true already declares the safety profile, so the description's added value is the note that the response includes per-platform publish status, which helps the agent anticipate return content. It says nothing about behavior for unknown IDs, permissions, or pagination, so it adds modest value beyond the annotation.

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 that names the resource, the selecting key, and the most notable return content with 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 simple one-parameter read tool with annotations covering safety and no output schema to explain return values, the description is close to sufficient: it covers what is fetched and hints at the response shape. Missing only minor operational detail such as behavior on a nonexistent ID.

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?

There is a single required parameter with 0% schema description coverage, so the description carries some burden; "by ID" conveys that the argument identifies one specific post. It does not specify the ID format (numeric, UUID, platform-prefixed) or where such an ID comes from (e.g., list_posts), leaving a real gap for the one parameter that must be supplied.

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 states a specific verb and resource ("Get a single post by ID") and clarifies scope with "single", which implicitly separates it from list_posts. It does not explicitly name or distinguish against get_post_stats, so it stops short of full sibling differentiation.

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: "by ID" tells the agent it must already have a post ID, but there is no statement about when to prefer this over get_post_stats or list_posts, nor any prerequisite or exclusion guidance.

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