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

Beyond the readOnlyHint annotation, the description discloses credit cost, account requirement with signup link behavior, and source details (reddit via RSS, newest-first, ~20). This adds meaningful behavioral context.

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 tightly packed: main purpose, kind parameter, source/ordering, cost, and account requirement are each conveyed in brief clauses. It front-loads the purpose.

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 covers the core semantics, source, ordering, cost, and account prerequisite. It doesn't explicitly describe the return structure, but that is implicit in 'fetch submissions or comments'.

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 description clarifies the kind parameter ('kind=submissions|comments (default submissions)') and hints at the limit default (~20). The schema already documents platform and username, so this complements rather than repeats.

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 first sentence 'Fetch a user's recent submissions or comments' clearly states the tool's function with a specific verb and resource, and the kind parameter specification distinguishes it from sibling tools like social_get_user or social_get_post.

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 gives implied usage context (fetching recent activity for a user) but does not explicitly name alternatives or state when not to use this tool. It mentions credit cost and account requirement, which are prerequisites, but no exclusions.

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