Get Package README

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

Annotations declare read-only, idempotent, open-world, and non-destructive, and the description adds substantial behavioral detail beyond that: verbatim markdown for npm/PyPI, HTML-converted-to-text for Cargo, truncation at 12000 chars with a 'truncated' flag, fallback via jsDelivr, and explicit 'never fabricates content' error handling. This is rich, non-obvious context that fully informs the agent of side effects and output nuances.

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 paragraphs: purpose, ecosystem nuances, args, return format, error handling. It is longer than average, but the complexity of three registries and important caveats (truncation, HTML conversion, fallback) justifies the length. The 'Args' section is somewhat redundant with the schema, preventing a perfect score, but every other sentence earns its place.

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?

There is no output schema, so the description must document return values, and it does: 'readme', 'truncated', 'source_url', 'fetched_at'. It also covers truncation length, error behavior, fallback logic, and per-ecosystem differences. Combined with rich annotations and a small param count, this description is exceptionally complete for the tool's complexity.

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?

The input schema already provides 100% coverage of all three parameters, including defaults ('version' description notes it defaults to latest) and enums. The description's 'Args' section largely repeats this schema information without adding new parameter-level semantics. The ecosystem-specific differences (e.g., Cargo returns HTML-converted-to-text) are more behavioral than parameter semantics, so the description adds only marginal value beyond the schema.

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 opens with a highly specific verb and resource: 'Fetch the real README/description for a package, straight from the registry.' It immediately distinguishes itself from sibling tools by emphasizing 'not a summary, not a paraphrase, not AI-generated,' which contrasts with docs_search_docs or docs_get_package_info. The per-ecosystem details further clarify scope.

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 description clearly indicates when to use this tool: when you need the exact, unmodified README rather than a synthesized or summarized description. It explains the behavior across npm, PyPI, and Cargo, giving context on what 'real' means per ecosystem. However, it does not explicitly name sibling tools or state when not to use this tool, so it lacks explicit exclusions/alternatives.

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