rank_changes

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

With no annotations, the description bears full responsibility for behavioral disclosure. It states it compares periods and finds significant changes, but does not explain how periods are defined, whether the operation is read-only, or any impacts. The description is too minimal to convey important behavioral traits.

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 extremely concise at two short sentences with no wasted words. It is front-loaded with the main action and then details the result. Every word 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?

Given no output schema and no annotations, the description should provide more context about the return format (e.g., list of queries with change metrics) and how the two periods are determined. The current description only covers the basic purpose, leaving significant gaps for a tool with 2 optional parameters.

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%, so baseline is 3. The description adds value by clarifying that the tool compares 'two periods' (implying the 'days' parameter defines the length of each period or the lookback window), which goes beyond the schema's description of 'days' as 'period length'. This contextualizes the parameter meaning.

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 clearly states the tool compares position changes between two periods and finds queries that gained or lost positions. The verb 'compare' and resources 'position changes' and 'queries' are specific. It distinguishes from siblings like 'detect_cannibalization' and 'page_queries' by focusing on rank shifts over time, though no explicit differentiation is given.

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?

No guidance is provided on when to use this tool vs alternatives (siblings). There is no mention of prerequisites, context, or exclusions, leaving the agent to infer usage from purpose alone.

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