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

Annotations already declare readOnlyHint, so the trailing 'Read-only' is redundant, but the description adds real behavioral context the annotations do not carry: a hard cap of 15 results, an explicit teaser/not-bulk-export limitation, and the fact that the response contains an app link. That is meaningful expectation-setting beyond the safety hint.

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 short sentences, front-loaded with the core action and result cap, then the limitation. The only wasted clause is 'Read-only,' which merely restates readOnlyHint=true from the annotations.

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 zero-required-parameter, read-only screening tool with full schema coverage and no nested objects, the description covers scope, result cap, teaser limitation, and that an app link follows. Nothing an agent needs to call it correctly is missing.

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% and both parameters (sector with partial match, min_score 0-100) are fully documented in the schema. The description adds nothing about either filter, so baseline 3 applies.

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 (screen) and resource (the Returnolio universe) plus the output shape (up to 15 top-scored names). It does not explicitly differentiate itself from near-siblings such as screen_companies or get_top10, so the agent must infer the boundary, but the purpose itself is 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?

The description scopes usage by declaring this a 'teaser, not a bulk export' and defers the full screener to the app, which implies when this is the right call. However, it never names an alternative tool (e.g. screen_companies, get_top10, get_stock_score) or the condition that would select one, leaving the routing decision to inference.

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