get_number_of_owners

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, covering the safety profile. The description adds genuine value beyond those by disclosing the output's nature: fields are upstream passthrough (not a fabricated aggregation) and summary fields describe the full source history rather than the current page. This is useful, non-contradictory behavioral context for an agent consuming the result.

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 primary action is front-loaded in the first sentence, and the whole description is compact. Minor style blemishes (uncapitalized 'data' and 'Not' at sentence starts, and a run of short fragments in the second sentence) keep it from a 5, but there is no wasted verbiage.

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 low-complexity paged read (3 params, 1 required, no nesting) with an output schema present and annotations covering safety, the description covers what matters: pagination behavior, output nature, and scope exclusion. The main gaps—unnamed sibling alternatives and no explicit limit/offset explanation—are minor given the strong structured metadata, so it lands just above baseline.

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 low at 33% (only order_book_id is described), so the description should compensate. The phrase 'Page Avanza ownersPoints in source order' implicitly covers limit/offset semantics by signaling pagination behavior, but it never explicitly explains what limit and offset do. The description partially compensates for the coverage gap but not fully, warranting a mid score.

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 gives a specific verb+resource ('Page Avanza ownersPoints in source order') that distinguishes this from the many get_* siblings spanning certificates, funds, futures, stocks, and warrants. However, there is tension with the tool name: 'get_number_of_owners' implies a count, while the description explicitly says there is no fabricated top-level owner count. That naming mismatch slightly muddies the purpose, keeping it from a 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?

The only usage guidance is the negative scoping clause 'Not market-wide ownership,' which tells the agent what this tool is not for. No specific alternative sibling is named, nor are selection conditions given (e.g., when to prefer get_stock_info or get_orderbook). The context is implied rather than explicit, so it stops at a 3.

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