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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is clear. The description adds valuable behavioral details: it returns 404 when the filing has no income statement, debits 28 credits even on failure or non-SEC filings, supports light_weight_mode, and specifies the API endpoint. This goes beyond what annotations alone provide.

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 information-dense yet well-structured, leading with the core purpose, then identification methods, shortcut relationship, error behavior, scope, cost, and options. Every sentence contributes essential facts; there is no fluff. It remains a single paragraph but is easy to scan due to logical flow.

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?

With no output schema, the description carries the burden of explaining return values — it states the response contains 'extracted line items with values and periods.' It also covers error cases, scope limitations, credit cost, and the optional payload mode. Given the tool's complexity (6 params, no output schema), this is adequate, though a more detailed response shape might be expected for a financial statement tool.

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 each parameter already has a description. The tool description adds meaning by clarifying the identification logic (filing_id OR ticker + fiscal_year, with optional quarter) and explaining the purpose of light_weight_mode ('leaner payload... saves context'). This supplements the schema without redundancy.

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 it returns the filing's Income Statement with extracted line items, values, and periods, and specifies identification methods (filing_id or ticker + fiscal_year). It distinguishes itself as a fixed shortcut for get_filing_statement with a specific statement type, and the sibling list includes other statement tools, so an agent can easily tell this apart from get_balance_sheet or get_cash_flow_statement.

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 explains it is a shortcut for get_filing_statement(statement_type='Income Statement') and notes it does not accept role_label or statement_type, implying the general tool is for other statements. It also mentions the SEC-only scope and the 404 case, but does not explicitly say 'use this for income statements, use get_balance_sheet for balance sheets' — though the shortcut nature and sibling names provide adequate context.

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