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

Annotations already declare readOnlyHint, idempotentHint, non-destructive and openWorldHint=false, so the safety profile is fully carried by structured data. The description's only added value is disclosing what is returned (version/repo/release count/release-notes source), which matters because no output schema exists, but it says nothing about lookup failures, missing packages, or ecosystem-dependent behavior.

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?

A single compact sentence with no filler, and the most important returned fields are front-loaded. It is a grammatical fragment with no leading verb, which slightly reduces immediate clarity about the action being taken.

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 two-parameter read-only lookup with no output schema, describing the returned fields is the right instinct and mostly sufficient. However, with eight similar siblings and an ecosystem switch, the agent is not told what 'latest stable' means per ecosystem, nor how to handle a package that has no repository or release notes.

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%, with 'name' (example 'flask') and 'ecosystem' (default PyPI, PyPI or npm) both documented in the schema. The description adds no meaning beyond that—it never mentions that the returned fields vary by ecosystem or how the package name is resolved.

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 enumerates returned data fields (versions, repository, release count, release-notes source) but never states a verb or resource action, so the agent must infer from the tool name and title that this is a package-metadata lookup. It also does nothing to separate itself from siblings such as what_changed or vulnerabilities, which also concern package data.

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?

There is no indication of when to call this versus the eight siblings (native_check, peer_check, types_check, upgrade_check, etc.). The agent gets a list of outputs but no routing criteria, prerequisites, or exclusions.

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