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

The description discloses several behavioral traits beyond the readOnlyHint annotation: it calculates a specific index using deps.dev data, provides weekly history, and notably mentions that the history series requires Gold tier (otherwise a snapshot is returned). It also states the update frequency (weekly) and the nature of the output (current snapshot or daily history). This is rich contextual information that goes well beyond annotations.

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 paragraph that leads with the primary output, then lists use cases, and ends with update frequency. Every sentence adds value without unnecessary fluff, making it both concise and well-structured.

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 tool with a single optional parameter and no output schema, the description provides thorough context: the output includes weekly history, top_drivers, and audit-ready source lineage; the computation methodology; supported ecosystems; and update cadence. It also explains the Gold tier dependency for history, covering the key edge case. The description is sufficiently complete for the tool's complexity.

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 already provides 100% coverage for the single optional 'days' parameter, including its purpose, range, and Gold tier behavior. The description mentions 'weekly history' but does not add additional parameter semantics beyond what the schema already documents. Baseline 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 clearly states the tool returns a 0-100 software supply-chain vulnerability pressure index, with specific details about the computation (per-package CVSS3 sums, npm/PyPI, deps.dev), output components (weekly history, top_drivers, source lineage), and update frequency. The verb 'Returns' and the specific resource make it distinct from sibling tools.

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 explicitly lists when to call the tool: open-source dependency risk, CVE/CVSS trends, npm/PyPI security, supply-chain attacks, and timing dependency upgrades or patch prioritization. It provides clear context but does not mention exclusions or explicitly compare to alternative sibling tools.

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