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

Annotations already provide readOnlyHint=true, and the description adds useful behavioral context: only public-safe fields are returned, no fair value per row, and results are ranked by Equity Rank Score. This goes beyond the schema and annotations without contradicting them.

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?

Three sentences, each earning its place: the first defines the output, the second enumerates valid sector values, and the third clarifies scope and points to the alternative. The most important information is front-loaded, with no filler.

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?

There is no output schema, so the description must explain the return shape; it lists all key fields per row. It also covers sector value flexibility, the public-safe limitation, and the fair-value alternative, making it complete enough for an agent to call this tool correctly without additional context.

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% for both limit and sector, so the baseline is 3. The description adds meaningful value by enumerating the accepted sectors and noting that finer labels like 'Banks' or 'Software' also match, which helps the agent construct valid sector values beyond the schema's single example.

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 names a specific action (list) and resource (a sector's scored stocks), and details exactly what each row contains: Equity Rank Score, margin-of-safety differential, P/E, market cap, and dividend yield. It also distinguishes itself from get_stock_valuation by explicitly stating fair value is not included, making the tool's purpose 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?

It clearly states when this tool is appropriate (public sector index, scored stocks) and explicitly routes fair-value needs to get_stock_valuation. It does not contrast with search or fetch, but the context is strong enough that an agent can infer when to use it over those siblings.

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