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

Annotations already declare readOnlyHint=true and openWorldHint=true, which inform the agent this is a safe read operation. The description adds no behavioral detail beyond that—no mention of response format, potential errors, or side effects. It does not contradict the annotations, but it also contributes no extra transparency, so the score matches the baseline for annotation-covered tools.

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, concise sentence that is front-loaded with the essential information: the action and the parameter. Every word earns its place, and there is no unnecessary verbosity. This is exemplary for a simple tool.

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 tool with a single parameter and no output schema, the description provides enough information for an agent to invoke it correctly: it takes a URL and returns the post. Given the tool's low complexity and the annotations covering safety, the description is adequate, though it could hint at what the response contains (e.g., post metadata and content) to be more complete.

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?

The schema already provides 100% coverage of the single parameter 'url' with the description 'Link to the Reddit post.' The description text 'by URL' merely reiterates what the schema conveys, adding no new meaning. With full schema coverage, the baseline of 3 is appropriate.

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 clearly states the action ('Get'), the resource ('Reddit post'), and the identifying mechanism ('by URL'). It is specific and not a tautology, though it does not explicitly differentiate from sibling tools like reddit_post_comments_list or reddit_post_transcript_get. However, the single-purpose nature of a post fetch makes it unambiguous.

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?

No guidance is provided on when to use this tool versus alternatives such as reddit_post_comments_list for comments or reddit_post_transcript_get for transcripts. The description simply states what it does without any context about selection criteria, prerequisites, or what constitutes an appropriate use case.

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