Latest package version

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

No annotations at all, so the description carries the full burden. It usefully discloses data provenance (live registry, "your training data is out of date") and the extra payloads returned, but says nothing about rate limits, behavior on unknown/deprecated packages, or that the operation is a non-mutating read — all of which an agent would want when batching up to 50 packages.

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?

Two sentences, both load-bearing: the first establishes what is fetched and from where, the second front-loads the imperative directive the agent needs before acting. No filler or repetition of the schema.

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?

With no output schema, the description helpfully previews the return shape (latest stable version, deprecation notices, vulnerabilities) and grounds it in live-registry freshness. It is nearly complete for a 2-param, read-only lookup; only batch-size and unknown-package behavior are unaddressed.

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 only 50% (the `ecosystem` enum has no schema description), so the description must compensate — and it partly does by mapping "crates.io" and "Go proxy" onto the enum values. But it never mentions the 50-package cap, batch semantics, or what a package spec string may include, so the compensating detail is partial.

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 ("look up the CURRENT latest stable version of packages") with the ecosystems named explicitly (npm, PyPI, crates.io, Go proxy) and secondary payloads listed (deprecation notices, vulnerabilities). Clear enough to know exactly what it returns, but it never mentions the sibling `check_deps`, so the boundary between the two tools is left to inference.

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?

Strong, explicit triggers: "ALWAYS call this before writing an install command, adding a dependency, or pinning a version, instead of guessing from memory" — that is a genuine when-to-use rule with an anti-pattern called out. It lacks a named alternative (e.g. "use check_deps for auditing an existing manifest"), so it stops short of full routing guidance.

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