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

The 'readOnlyHint' annotation already tells the agent this is a read-only operation, so the description doesn't need to restate that. The description adds useful context about the scope (SEC data, not market data) and the 12-pack structure. No contradictions with annotations are present.

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 two concise sentences with no fluff. The first sentence establishes the core value (certified packs, with an example), and the second sentence clarifies exclusions. Every word 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?

The tool has 4 parameters (all described in schema), an output schema, and strong annotations. The description adequately covers the domain and exclusions. It doesn't explain the return format, but that's covered by the output schema. Minor gap: it doesn't clarify that 'period' is optional, but the schema does.

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 100%, and all parameters are described clearly in the schema. The description doesn't add new meaning beyond stating the packs are 'certified' and listing 'dcf_valuation_inputs historical FCF' as an example. Baseline 3 is appropriate since the schema already does the heavy lifting.

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 the tool retrieves certified SEC/EDGAR valuation input packs and explicitly lists 12 packs including 'dcf_valuation_inputs historical FCF'. It distinguishes itself from siblings by specifying what it does NOT provide ('Not market EV, P/E...'), helping an agent differentiate it from nearby tools like 'query_sec_metric_exact' or 'lattice_arith_evaluate'.

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 tells the agent when to use this tool—for certified SEC valuation packs—and crucially, what not to use it for (market EV, P/E, trading DCF, macro gauges). This is strong guidance. However, it doesn't mention alternatives explicitly (e.g., 'use query_sec_metric_exact for single metrics'), so it falls just short of a 5.

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