xbrl_segment_breakdown

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

Annotations already indicate readOnlyHint and idempotentHint. The description adds that it returns a JSON with values and percentages and accepts an optional dimension filter, providing behavioral context beyond annotations without contradicting them.

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 concise with 6 sentences, well-structured with separate sections for purpose, args, and returns. No unnecessary words or fluff.

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?

The description covers purpose, parameters, and return type. While it could mention that a loaded filing is required (implied by param description), it is otherwise complete for this tool, especially with existing output schema.

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 0% for the top-level 'params' parameter, but the sub-properties have descriptions. The description summarizes the parameters as 'Filing ID, concept name, optional dimension filter,' adding context that compensates for the missing top-level description and clarifying the optional nature of dimension filter.

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 'Extract dimensional breakdowns for a concept' and explains that it shows how totals break down by segments, geographies, etc., which distinguishes it from sibling tools like xbrl_fact_details.

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 description implies usage for dimensional breakdowns but does not explicitly state when to use this tool vs alternatives or mention when not to use it. No mention of prerequisites or exclusions.

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