compare_search_periods

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint, covering the safety profile. The description adds no behavioral context beyond that, such as how the comparison is computed, whether missing data is handled, or any rate/latency characteristics. It is not contradictory, just thin.

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 one-line purpose is front-loaded and clean, followed by a structured Args block. The Args list largely mirrors schema titles/defaults, which is slightly redundant, but it is efficient and appropriately sized for a 7-parameter tool.

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?

An output schema exists, so return values need not be explained. However, for a comparison tool the description omits constraints that affect correct invocation, e.g. whether periods should be equal length or how the deltas are framed. Adequate but with a clear gap.

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 0%, so the description must carry the burden, and it does add real meaning: 'Exact GSC property URL', the YYYY-MM-DD date format, and semantics for dimensions ('to group by') and limit ('top N'). It falls short of enumerating allowed dimension values or confirming the date format applies to all four period fields.

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 and resource: 'Compare search analytics between two time periods.' That clearly distinguishes it from get_search_analytics and get_advanced_search_analytics, which are single-period analysis. It stops short of naming those siblings or explicit scope boundaries, so it scores a solid 4 rather than 5.

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?

Only the implied context 'between two time periods' signals when to use it. There is no statement of when-not to use it or which sibling (compare_seo_audits, compare_project_audits, get_search_analytics) an agent should pick instead, and no prerequisites such as whether both periods must be equal length.

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