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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world scope, so the safety profile is covered. The description adds that results are ordered by first-ship date and include lag in days, but says nothing about how adoption is measured or how ties/unknowns are handled. Useful but modest added context against already-rich 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?

Two sentences with no filler: the first defines the output ordering and payload, the second handles the successor relationship. The core answer ('who shipped first, who followed, lag in days') is front-loaded.

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 one-parameter, read-only query with an output schema and full annotation coverage, the description supplies everything needed to call it correctly. Only a hint about scope (tracked tools only? all time?) is absent.

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% and the schema already documents the single 'feature' parameter as 'Feature id or substring'. The description slightly reinforces this by naming concrete example values (mcp-oauth, subagents, planning), confirming that loose human-readable names work, though it doesn't restate matching rules such as case sensitivity.

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 analysis: who shipped a given cross-tool feature first, which tools followed, and the day-lag. The enumeration of example features (MCP support, subagents, planning mode, hooks, checkpoints) and the 'Successor to feature_timeline' note let an agent separate it from the near-named sibling without opening either 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?

'Successor to feature_timeline' gives an implicit routing rule: prefer this tool over the older one for feature-shipping questions. It does not state any when-not conditions or name other plausible alternatives (e.g. compare_tools for general tool comparison), so the guidance is clear but not exhaustive.

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