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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint=false. The description adds useful behavioral context: it returns action_allowed, vulnerability delta, compatibility, EOL, and breaking-change evidence, and clarifies that it does not produce migration steps. This goes beyond what annotations alone provide.

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?

Every sentence earns its place: use case, return value summary, alternative tool, exclusions, and safety. The critical context is front-loaded and the description is tight despite covering a lot of ground.

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 a rich output schema, detailed annotations, and clear sibling distinctions, the description covers everything needed to select and invoke the tool correctly. It explains what the tool returns, when to use it, when not to use it, and which alternative to prefer.

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 description coverage is 80%, so the schema already documents most parameters. The description reinforces that exact versions are expected ('between two exact versions') but does not add substantial new meaning beyond the schema fields.

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: assessing a known npm/PyPI dependency upgrade between two exact versions. It clearly differentiates from plan_dependency_upgrade and explicitly lists exclusions such as choosing a target, installing packages, or analyzing other ecosystems.

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?

Provides explicit when-to-use guidance ('needs a cited go/no-go risk decision without steps'), names the alternative (plan_dependency_upgrade), and lists concrete negative use cases. An agent can route correctly without additional inference.

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