get_package_stability

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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so 'Read-only lookup' is largely redundant. The description earns credit for what annotations cannot convey: it enumerates the returned signals (publish timestamp, 90-day velocity, 0-100 stability score, tools/list drift risk, before/after migration code), which is meaningful given there is no output 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?

Two sentences, zero filler: the capability and returned signals come first, the disambiguation against the sibling last. The output enumeration is dense but each item carries information an agent needs absent an output 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?

For a single-parameter, read-only, non-destructive lookup with no output schema, the description supplies the return-value surface, the input scoping rule, and the sibling routing. Nothing material is missing for correct invocation.

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% and already supplies examples, so the baseline is 3. The description still adds semantic framing — the package must resolve to 'a single AI Agent SDK or MCP server' and may be a name or a slug — clarifying that scoped/glob or multi-package inputs are not intended.

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 ('Read-only lookup') plus a precisely scoped resource ('live npm or PyPI version... for a single AI Agent SDK or MCP server'), and it enumerates exactly what the lookup returns. An agent can distinguish this from check_stack_drift without opening the 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?

Explicitly routes the agent: 'Prefer this over check_stack_drift when inspecting one specific package by name or slug,' which implies the sibling for multi-package/stack-level checks. It does not address the other siblings (list_volatile_packages, get_archived_mcp_replacements), so the coverage of alternatives is partial rather than complete.

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