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

Annotations already fully cover the safety profile (readOnlyHint=true, openWorldHint=true, idempotentHint=true, destructiveHint=false), so the bar is lower. The description adds the data source and an interpretive framing ('community interest') and implies results are dynamic since 'most recently measured' shifts over time, but it does not disclose operational details such as ordering guarantees or time windows. No contradiction with annotations.

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 front-loaded sentence with the verb and resource up front. The closing clause ('showing current community interest in bundle-size analysis') adds interpretive value that aids purpose clarity rather than pure filler, keeping the entry compact and efficient.

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 low-complexity tool with zero required parameters, a fully documented parameter, comprehensive annotations, and an existing output schema, the description is largely sufficient. The only minor gaps are implicit ordering (recency) and a lack of any stated time window, which are easily inferred from 'most recently measured.'

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% — the limit parameter is already fully documented as 'Max entries to return (default 25)'. The description adds nothing about parameters, so it sits at the baseline for tools whose schema does the heavy lifting.

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 ('Return'), resource ('npm packages most recently measured on bundlephobia.com'), and interpretive context ('showing current community interest'). The domain mention clearly distinguishes it from sibling tools like recent_alerts and recent_changes without needing to open any schema.

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?

Usage context is implied through domain-specific language — an agent can infer it is for fetching recently measured npm packages or gauging community bundle-size interest. However, it never explicitly says when to choose this over sibling tools like pipeworx_trending, discover_tools, or recent_changes, and names no alternatives or exclusions.

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