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

Annotations already establish read-only, idempotent, open-world, and non-destructive behavior. The description adds meaningful behavioral context beyond that: it returns data 'across every reported period,' provides a full concept index, and lets `accession` override the company-level modes — all useful expectations for an agent.

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?

Two sentences with no filler. The first sentence front-loads the core purpose and default behavior; the second covers the two specialized parameters compactly. Every clause earns its place.

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 tool with six optional parameters and no output schema, the description gives a solid mental model of what comes back. It covers the default output, the optional overrides, and the filing-scoped behavior. A slightly fuller note on the JSON return format or company-identifier requirements would make it fully complete, but the current level is strong.

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%, so the baseline is 3. The description adds value by explaining that `concept` retrieves 'raw time series' beyond the 'curated fundamentals' and that `accession` returns 'every XBRL concept reported in that one filing,' clarifying the intent of those parameters beyond their schema descriptions.

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 names a specific action and resource: 'full XBRL-to-JSON converter' for SEC XBRL data. It then enumerates concrete outputs — normalized income statement, balance sheet, cash flow, and a concept index — making its purpose unmistakable and distinct from financial-data siblings.

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 explains three usage modes: the default normalized-statement output, passing `concept` for raw tag time series, and passing `accession` for single-filing concept dumps. This gives clear contextual guidance, though it does not explicitly contrast with siblings like get_fundamentals or get_filings, so it falls short of a full 5.

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