hourly_performance

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so safety is covered. The description adds real behavioral context beyond them: the 10-day cap, that the most recent points are preliminary/incomplete, and that Search Console's native daily numbers are Pacific-Time days while timezone re-cuts them into local days/hours.

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?

Three short, front-loaded paragraphs: the core identity statement, the hours=24 vs days branch, and the timezone nuance. Sentence economy is good, though the timezone paragraph is dense and could be marginally tighter.

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 described, and the temporal/timezone semantics are well covered. However, with 8 parameters at 0% schema description coverage and no mention of the filter or search-type parameters, the description leaves notable gaps for an otherwise complex tool.

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% across 8 parameters, so the description must carry parameter meaning. It explains by, days, hours, and timezone well (including the local-time re-cutting semantics), but says nothing about site_url, page_filter, query_filter, or search_type, leaving half the parameters undocumented.

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 states a specific verb+resource (hourly Search Console performance data for the last 10 days) and explicitly differentiates its niche from siblings: it reproduces the Performance report's 24-hour view and is 'the only way to get true LOCAL days.' An agent can distinguish it from performance_overview and query_search_analytics without opening the 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?

It clearly specifies the branching condition: hours=24 reproduces the 24-hour report view including preliminary points, otherwise the last `days` (max 10) are returned. The timezone behavior (re-cut into local days via by=day or per local hour via by=hour) tells the agent when to use which mode. No explicit exclusion or sibling routing by name, but usage context is unambiguous.

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