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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the behavioral nuance that results are limited to cross-subreddit pairs and that the tool surfaces 'hidden links' — useful context beyond the annotations. However, it doesn't disclose details like whether results are ranked by similarity strength or how 'semantically similar' is determined.

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, information-dense sentence followed by three short example queries. Every word earns its place: the core function, the cross-subreddit constraint, the value proposition, and usage examples are all front-loaded with zero waste.

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 read-only, idempotent tool with one fully-documented parameter and no output schema, the description covers the essential context: what it does, what makes it unique, and when to use it. The only minor gap is the lack of detail about the return format, but since there's no output schema and the tool is simple, this is a small omission.

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 100% — the only parameter (limit) is fully documented in the schema with default and max values. The description doesn't add parameter-level detail, but 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 states a specific verb ('Find'), a specific resource ('semantically similar posts saved from DIFFERENT subreddits'), and the unique value proposition ('surfaces hidden links between interests'). It clearly distinguishes itself from siblings like find_similar_posts and find_debates by emphasizing cross-subreddit connections.

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?

The description provides explicit example queries ('what connects my saves?', 'find cross-subreddit themes', 'surprising connections') that signal when to use this tool. It doesn't explicitly state when not to use it or name alternatives, but the examples and the 'DIFFERENT subreddits' emphasis make the usage context clear.

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