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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds 'Read-only and safe to retry,' which largely repeats those annotations rather than adding new behavioral context like auth needs or return-format caveats. Since the bar is lower with annotations and no contradiction exists, a 3 is appropriate.

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?

Three sentences, each earning its place: the first defines the deliverable, the second routes to the sibling, the third lists exclusions. Information is front-loaded with the most important condition first and no redundancy. This is a model of concise, structured tool documentation.

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 at this complexity (5 params, nested runtime object, output schema), the description covers trigger conditions, deliverable contents, alternative tool, and explicit non-goals. The output schema handles return-value details, and annotations cover safety, so nothing needed for correct invocation is missing. Complete.

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 covers 80% of the parameters with clear descriptions (exact package name, ecosystem enum with only npm/pypi, exact current/target versions). The description reinforces that versions are exact and tied to npm/PyPI, adding marginal clarity over the schema. Baseline 3 holds because the schema does the heavy lifting and the description doesn't add new parameter-level semantics beyond naming use cases.

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?

States a specific verb and resource: produces a migration checklist with refactor actions, ordered review actions, changelog links, or test steps for exact npm/PyPI versions. Explicitly contrasts with check_dependency_upgrade, distinguishing itself as the step-by-step planner rather than a go/no-go check. Clear scope that lets an agent select it 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 states when to use ('Use when a coding agent needs...') and names the alternative ('Use check_dependency_upgrade instead for a go/no-go without steps'). Provides exclusions ('Do not use to choose a target, install a package, or provide a general tutorial'). This is exactly the when/when-not/alternatives guidance that earns a 5.

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