packageSearch

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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior. The description adds critical behavioral details: searchLimit defaults (1 for known, 5 for alternatives), Python returns only 1 result, naming conventions (dashes vs underscores), and the need to check deprecation warnings. No contradictions.

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?

The description is well-structured with clear sections (titles, when, fromTool, toTool, vsGitHub, gotchas, examples). It is comprehensive without being overly verbose. Slightly more concise could be achieved, but it is appropriate for the tool's complexity.

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?

Given the complexity of the tool (multi-parameter array, two ecosystems), the description covers all essential aspects: external APIs, behavior differences, pagination, deprecation, and integration with sibling tools. The schema and output schema handle the rest, leaving no gaps.

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% with detailed property descriptions. The description adds value through <gotchas> (e.g., Python always returns 1, naming conventions) and <examples> (concrete usage of name and ecosystem). This exceeds the baseline but not by a large margin.

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?

Title and description clearly state 'Find NPM/Python packages' and specify that it provides repository URLs. The <vsGitHub> section explicitly distinguishes from githubSearchRepositories, making the purpose specific and unambiguous.

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?

The <when> section lists clear use cases: lookup by name, get repo URL, compare alternatives, check deprecation. The <fromTool> and <toTool> sections provide chaining guidance, and <vsGitHub> advises using this tool first for known names versus githubSearchRepositories for broad discovery.

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