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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds behavioral context beyond that: results are ordered newest-first and include counts per change type. It omits pagination behavior (the cursor param) and any note on result size, which keeps it from a 5.

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, zero filler. The positive usage condition and the returned shape come first, the exclusion and sibling redirect second — exactly the right front-loading.

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 9-parameter, read-only list tool with no output schema and only 56% schema description coverage, the description covers what the tool returns and when to use it, but leaves pagination (cursor/limit) and the response_format/context params entirely to an incomplete schema. Adequate but with clear 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 56%, so it sits near the baseline where the schema does most of the work. The description does add value by naming the concrete change-type vocabulary the `types` filter operates on and framing the store scope, though it says nothing about limit, cursor, region, or response_format.

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+resource (list changes in a store) and enumerates the change categories (chart moves, featuring, launches, delistings, metric moves, MCP changes) plus the ordering (newest first). This is enough for an agent to distinguish it from charts_get and other siblings 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?

Gives an explicit when-to-use trigger ('user asks what changed in a store') and an explicit when-not with a named alternative: 'Do not use for a chart's full current order; use charts_get.' Nothing is left to inference.

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