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

Annotations already declare a safe read-only open-world operation, and the description adds substantive behavior beyond them: live registry reads on each call, a 60/minute per-client rate limit, 404-style errors for unknown names, a warning field on format changes, and a 60-minute handle retention policy. This is unusually complete operational disclosure.

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 core purpose is front-loaded and each subsequent sentence carries distinct operational information (registry scope, rate limit, error semantics, retention). It is dense but nothing is redundant; only the bundled final clauses could be split for readability.

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?

An output schema exists, so return formatting need not be spelled out, yet the description still enumerates the fields returned. Combined with error, rate-limit, and retention behavior, an agent has everything needed to call this 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 the two parameters are already documented, setting a baseline of 3. The description nevertheless adds meaning by ruling out a version parameter and framing both params as registry-scoped, which prevents a plausible invocation error.

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 names a specific verb (Get) and resource (a package's latest release) and scopes it to three named registries. It also distinguishes itself from the sibling read_page, so an agent can route correctly without opening either schema.

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 gives explicit selection criteria: 'Use this for those three registries; for any other site use read_page.' It also pre-empts a common misuse by stating that only the latest release is available and there is no version parameter.

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