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

Annotations already declare readOnlyHint=true, and the description adds that the data is public, figures are model estimates, and it is not advice, plus a citation URL. This gives an agent useful behavioral context beyond the schema and annotations with no contradiction.

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 front-loaded, compact, and dense with useful information: it lists the return fields in one sentence and adds a disclaimer in the next. There is no filler or repetition of schema details.

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 one simple required parameter, no output schema, and read-only annotations, the description covers invocation, return contents, source URL, and the model-estimate limitation. An agent has enough context to call the tool correctly and interpret its output.

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?

The input schema already fully documents `id` as a ticker symbol with an example. The description adds that the id is returned by `search`, which is helpful but only marginal additional semantic value beyond what the schema provides.

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 retrieves Equity Rank's public valuation summary for one security by ticker, and it enumerates the specific fields returned. It distinguishes itself from `search` and `list_sector_stocks` by framing the id as a ticker returned by `search`, but it does not explicitly differentiate itself from the similarly named `get_stock_valuation` sibling.

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 provides a clear use context: call this when you need a single security's valuation summary, and obtain the id from `search`. It does not explicitly state when not to use it or mention alternatives such as `get_stock_valuation`, so it stops short of full routing guidance.

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