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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and scope profile is covered structurally. The description adds behavioral value by characterizing the operation as a resolution step that produces richer instrument records with metadata suitable for follow-up, which goes beyond the annotations though it stops short of describing pagination or result shape.

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 with zero filler: the first front-loads the purpose, the second handles disambiguation. Every clause earns its place by routing the agent to a sibling or defining the selection condition.

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 an output schema and annotations covering the safety profile, the description needn't explain return values, and its routing plus output characterization is nearly sufficient for a one-parameter tool. It stops short of distinguishing itself from other google_finance siblings like quote or company, leaving minor residual ambiguity in a very crowded namespace.

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 the single parameter q already documents 'Search keyword or company name.' The description only adds that the query may be a ticker as well as a company, a marginal enrichment over the schema. Baseline 3 is appropriate when the schema carries the parameter detail.

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 states a specific verb and resource ('Resolve a company or ticker query into full Google Finance instrument context') and immediately contrasts the scope against siblings google_finance_search ('compact flat list') and google_finance_ticker ('focused ticker details'). An agent can distinguish this tool from its closest neighbors without opening a schema.

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 explicitly names two alternatives and the condition that selects each, then states the selection rule for this tool ('choose context when you need the richer instrument records and their available metadata'). This is precise when-to-use routing rather than implied guidance.

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