check_version_exists

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 the primary behavior: the tool returns whether the version exists along with package details and timestamp. The verb 'check' implies read-only operation, though it does not explicitly state side-effect-freeness or auth requirements, which are unlikely to be a concern for this type of lookup.

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 two sentences long and delivers the core purpose, and then direct use cases, and the return outcome. Every sentence contributes value without redundancy or filler.

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?

The description covers the tool's purpose, usage scenarios, and what the caller receives. The schema is complete with all parameters described. It does not differentiate from check_versions_exist explicitly, but the simple nature of the tool means the description is sufficiently complete for an agent to invoke it correctly.

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 input schema covers 100% of parameters with descriptions, so the tool description adds little extra meaning. The phrase 'specific version' aligns with package_name and version but does not enrich understanding beyond what the schema already provides. This is the baseline for full schema coverage.

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 'Check if a specific version exists,' which clearly identifies the action (checking) and resource (version existence). The word 'specific' distinguishes it from sibling tools like check_versions_exist, and it does not confuse with get_package_info or get_latest_version.

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 explicitly states 'Use for dependency validation, CI/CD checks, or ensuring version compatibility,' giving clear context for when to invoke the tool. It does not mention alternatives or exclusions, but the use cases are specific enough to guide the agent.

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