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

Annotations already declare readOnlyHint=true and openWorldHint=false, so safety is covered. The description adds that output shape varies by view (single-company series vs cross-company multiples), which is genuinely useful, but says nothing about rate limits, pagination, or how large an aggregation result can be.

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 tightly packed sentences with no filler, and the mode split is front-loaded ahead of the parameter rules. The semicolon-separated clauses are dense but readable.

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 an 11-parameter tool with no output schema, the description covers only view, symbolExchange, and type, leaving the aggregation filters (sector, country, minCap, maxCap, byname) and the return shape entirely to the schema. Adequate but with clear gaps for the aggregation path.

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%, so baseline is 3, but the description goes beyond per-field docs by explaining how parameters combine per mode (symbolExchange only with history, type only with aggregation). That relational guidance is not derivable from the individual schema entries.

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?

Names the resource (market capitalization) and splits it into two clearly labeled modes, history (one company) vs aggregation (multiples across companies), so an agent can distinguish it from siblings like prices or fundamentals. It lacks an explicit retrieval verb, but the resource and mode split are unambiguous.

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?

Gives explicit routing for each view and the required companion parameter (symbolExchange for history, type/pe,pb,ps,pc,liab for aggregation). It does not say when to prefer this tool over siblings such as fundamentals or benchmark, so it stops short of full when-not guidance.

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