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

Annotations declare readOnly/idempotent/openWorld safety, so the bar is lower, yet the description adds genuinely valuable context the annotations cannot: data provenance (endoflife.date, volunteer-maintained) and an advisory to confirm with the vendor for compliance decisions. It also documents what is returned in each mode (with vs without version), which exceeds annotation coverage.

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?

Front-loaded purpose, then usage, then return behavior, then caveat, then exclusion. All sentences earn their place, though it is on the longer side and the vendor-confirmation caveat slightly competes with the core guidance for attention.

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 purpose, when to use, when not to use, data source trustworthiness, and per-mode return behavior. With an output schema present, it need not detail field shapes, and it appropriately leaves those to structured data. Complete for an agent to call 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?

Schema coverage is 100%, so params are already documented, but the description adds meaning beyond the schema: the contrast between supplying a version (single cycle details) and omitting it (list of supported cycles), plus product-name examples. It slightly exceeds the baseline 3 by clarifying the consequence of each parameter choice.

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?

Specific verb+resource ('Get end-of-life status') with concrete scope, plus worked examples ('is Node.js 20 still supported?') that remove ambiguity. It also distinguishes itself from the sibling space by naming a plugin family (Package Health Check) for a different concern.

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 when-to-use (support/lifecycle questions) with two example phrasings, and an explicit when-not-to-use: 'Not for package vulnerabilities: use the Package Health Check plugin.' The alternative is named and the condition that selects it is stated.

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