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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower, yet the description still adds real behavior: it works on unpublished/draft/held articles and it validates that the article exists first, hinting at a failure mode. It omits whether the link expires or requires authentication to open.

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?

Two short sentences with no filler, front-loading what the tool returns before adding the scope and validation caveat. Every clause earns its place.

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 read-only tool with no output schema, the description explains the return value well (a link a human can open) and notes the existence check. Minor gaps remain around permissions and link lifetime, but nothing critical is missing for correct invocation.

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 only 50%: 'site' is documented in the schema, but 'id' carries no description anywhere. The description only refers obliquely to 'the article', so it does not compensate for the undocumented identifier parameter (format, accepted values, or lookup behavior).

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+resource (get a preview link for an article) and clarifies the return value is a human-openable URL rendered as Blawgy would render it, which separates it from get_article-style content retrieval. It does not name a sibling tool explicitly, so differentiation is implied rather than stated.

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 clear context for when this is the right tool: when you need a link a person can open, including for unpublished, draft and held articles that other endpoints would not expose. It stops short of naming alternatives (e.g. get_article) or stating when not to use it.

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