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

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered. The description adds real behavioral context beyond that: the data sources ('GitHub releases or CHANGELOG'), the output composition, the citation behavior, and the pricing/credits model, which is transaction-relevant for an agent.

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?

Front-loaded with the core purpose and output breakdown in a tight first sentence, followed by ecosystem and pricing lines. The $0.03 price is stated in both the title and the description, a minor redundancy, but nothing wasted overall.

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 full output schema, complete parameter descriptions and annotations present, the description only needs to frame intent and sourcing, which it does. It could go further by distinguishing this tool's role from the crowded sibling set, but it is functionally 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 description coverage is 100%, so the schema already documents name, from, to and ecosystem including the enum. The description only echoes the ecosystem list and version semantics, adding no format or constraint detail beyond the schema — baseline 3 applies.

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 ('Upgrade guide for a dependency') and then enumerates exactly what the guide contains: breaking changes, deprecations, new features, step-by-step migration. It is clearly distinguishable from siblings like package-changes or changelog, which don't synthesize a migration guide.

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 names ecosystem support ('For npm, PyPI, crates and Go') and the input pattern (your version and the target), implying when it applies. But it never states when to pick this over upgrade-fix, package-changes, compat-check, or changelog, nor any exclusions or prerequisites.

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