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

Annotations already declare readOnlyHint=true, and the description's 'Read-only' matches rather than contradicts. Beyond that it discloses real behavioral traits the annotations do not: a hard cap of 15 results, the teaser limitation, and that the response embeds an app link to the full screener.

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 tight sentences, front-loaded with the primary action and result cap before the limitation and the read-only note. The trailing 'Read-only' duplicates the annotation but costs little.

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 no output schema, the description carries the return-value burden and does so adequately by stating the count cap and the app link. What is missing is any note on ordering or scoring semantics of the returned names, but nothing essential to invoking it correctly is absent.

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%, so both parameters (sector partial match, min_score 0-100) are already documented in the schema. The description adds no filtering syntax or default behavior beyond that, so the 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?

Specific verb+resource ('Screen the Returnolio universe', return up to 15 top-scored names) that tells the agent exactly what comes back and how it is bounded. It does not explicitly distinguish itself from the closest sibling get_top10, which also returns a ranked list, leaving a small overlap ambiguity.

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?

Clear when-to-use framing: it is a 'teaser, not a bulk export' and the full filtered screener lives in the app, which tells the agent to stop here when bulk export is needed. It offers no explicit guidance against sibling tools such as get_top10 or compare_stocks, so the routing is only implicit.

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