security_fetch_package_licence

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

With no annotations, description carries full burden. It explicitly states 'Read-only. No side effects. Idempotent.' Describes caching (1-hour), source (deps.dev), and return value (SPDX identifier). Fully discloses behavior beyond schema.

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?

Description is comprehensive but slightly long. However, it is well-structured: purpose first, then parameter bullets, usage guidance, additional details. Every sentence adds value. Could be more compact but still effective.

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?

Covers all facets: parameters, return value, behavior, caching, source, usage context, alternatives, and feedback mechanism. Output schema exists but is not shown; description still notes return value. For a simple read-only data fetch, this is fully 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?

Schema coverage is 0% but description provides complete parameter documentation: examples for package (flask), version (2.3.0), and valid ecosystems list (PyPI, npm, etc.). Adds essential meaning beyond bare schema types.

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 the specific action (Fetch SPDX licence identifier) and resource (open source package version). It distinguishes from sibling tools like security_fetch_package_vulnerabilities and security_fetch_licence_analysis by specifying use case. The verb-resource pair is clear and unique.

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?

Explicit guidance: 'Use this to verify licence compatibility before including a dependency' and 'Use security_fetch_package_vulnerabilities instead when checking for security issues not licences.' Also provides fallback instruction for reporting gaps. This clearly tells when to use and when not to.

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