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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so safety is covered; the description adds genuinely new context by disclosing the result row shape (visitors, views, sessions, bounces, relative shares) and the underlying GET endpoints. It stays silent on pagination behavior and default sort, which the schema only partly covers.

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 sentences, front-loaded with what is returned and followed by filtering and result shape; almost every clause earns its place, though the endpoint URL list is mostly redundant with the title and schema.

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 34-parameter, no-output-schema tool the description usefully covers the dimension choice, filter semantics and result fields, plus the required domain_id is documented in the schema with a pointer to pirsch_list_domains. Pagination (limit/offset/next_offset) and sort defaults are left to the schema, which is acceptable but not fully complete.

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 100% across 34 parameters, so the schema already documents filters, prefix operators, dates and enums. The description only illustrates filter syntax with 'country=de, path=~blog', which restates what the schema already specifies, so baseline 3 applies.

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 concrete resource breakdown ('visitors per browser, browser version, operating system or screen class') that maps directly to the dimension enum, so the agent knows exactly what the tool returns. It does not name or distinguish itself from the closest sibling, pirsch_get_platforms, which reports overlapping platform data.

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 gives filter usage context ('Filters narrow the data (for example country=de, path=~blog)'), which is implied guidance for narrowing results, but never says when to choose this tool over pirsch_get_platforms or the other breakdown tools, and lists no exclusions or prerequisites beyond the required params in the schema.

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