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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the scope of the returned overview (sector, top companies, growth companies, research reports), but since an output schema exists this partly restates structured data rather than disclosing new behavior like freshness or coverage limits.

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 sentences, front-loaded with the action and identifier before the payload/use-case detail, with no filler. The second clause listing result contents is marginally redundant against the output schema but still reads efficiently.

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 a single-parameter, read-only lookup with an output schema, the description supplies enough to invoke the tool correctly and understand its scope. The only shortfall is not clarifying how the industry key relates to the sibling industries/sector tools.

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% for the single 'key' parameter, so the baseline is 3. The description calls it an 'industry identifier' while the schema says 'Sector or industry key', which is a slightly inconsistent framing rather than added meaning; no format or lookup guidance is provided.

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?

States a specific verb ('Fetch') and resource ('Yahoo Finance industry overview') keyed by an industry identifier, and the payload contents are enumerated. It is distinguishable from the list-style sibling yahoo_finance_industries, though it never explicitly contrasts itself with the analogous sector-level tool yahoo_finance_sector.

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?

Provides a clear use context ('use this to compare companies within one industry'), which tells the agent when the tool is appropriate. It stops short of naming alternatives or exclusions, so an agent must infer that it needs an already-known industry key rather than a company ticker.

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