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

With no annotations provided, the description carries the full burden. It discloses rate-limiting, the best-effort nature of Instagram/TikTok/X results without a paid key, and the concurrent check behavior. It does not explicitly state the tool is read-only or non-destructive, but the overall safety profile is clear.

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, dense paragraph that front-loads the core action and return format, then efficiently adds usage context and behavioral notes. Every sentence adds value with no redundant or vague statements.

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?

Despite lacking an output schema and annotations, the description provides a good mental model: it explains the return format, rate limits, API key tiers, and sibling relationships. It could improve by listing the exact default platforms or clarifying error handling, but overall it is sufficiently complete for the tool's simplicity.

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%, so the baseline is 3. The description adds context about the platforms parameter (default grid and Telegram exception) and that plan/userId are ignored. However, it does not significantly expand on the name parameter beyond what the schema provides.

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 opens with a specific verb and resource: 'Check username availability across the major social platforms concurrently.' It clearly distinguishes itself from sibling tools by noting it is 'Narrower than namesniper_check when domains are not needed' and explains the JSON return format with per-platform status and confidence scores.

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 usage guidance: 'if a wanted handle is taken, offer namesniper_watch' and contrasts with namesniper_check when domains are needed. It also explains the free vs. paid key context. However, it does not fully enumerate when not to use this tool (e.g., when domains or trademark checks are needed) beyond implying namesniper_check covers domains.

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