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

Annotations only declare readOnlyHint=true, but the description adds rich behavioral context: return shape, parallel-array alignment, null-vs-zero semantics, withheld pre-split per-share cells, IFRS/no-annual-fact error behavior, SEC EDGAR source, post-quarter lag, and 24h cache.

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?

Front-loads the core purpose, then efficiently packs only actionable details about output shape, units, null handling, basis, errors, alternatives, and source. The density is justified by the tool's complexity and lack of an output 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?

Given no output schema, the description fully explains the return object, key subfields, array alignment, error responses, data source, lag, and caching. An agent has enough context to call and interpret the tool correctly.

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% and the sole parameter is already documented as a stock ticker symbol. The description reinforces that it takes one ticker but adds no syntax or format details beyond the schema, so the 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?

States a specific verb and resource: full XBRL financial history for one ticker. It clearly distinguishes the tool from siblings by naming related alternatives for cash deployment, per-share fair value, and industry operating metrics.

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?

Explicitly routes agents to get_capital_allocation, ol_intrinsic_value, and ol_operating_kpis for specific alternative needs. This makes when-to-use-this-versus-siblings clear without requiring schema inspection.

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