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 only the default values, which are already in the schema, and does not disclose pagination behavior or what 'metric id' actually controls.

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 short sentences, front-loaded with purpose. Slight redundancy in restating the schema defaults, but no wasted prose.

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?

Output schema and annotations exist, so return values and safety needn't be explained. Still, for a tool whose key input is an opaque integer metric id, the description leaves the agent without enough to choose a metric confidently.

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 baseline is 3. The description merely restates the defaults already documented in the schema and adds no meaning about what metric id 6 represents or how values map to ranking dimensions.

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 ('List') and resource ('top Google Finance stocks ranked by a metric'), so an agent knows it returns a ranked stock list. However, it doesn't differentiate itself from siblings like google_finance_markets_movers, trending, or featured, which could also return ranked stock lists.

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?

'Use these inputs to browse a ranked stock list' implies browsing usage but gives no explicit when-to-use guidance or named alternatives. With closely related siblings (movers, trending, indices), the agent gets no signal about which tool to pick.

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