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 nothing beyond that: it does not say what 'related instruments' means (peers, competitors, same-sector equities), how many are returned, or whether the symbol must already be resolved.

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?

The sentence is short, but the problem is under-specification rather than economy of words. A single noun phrase with no verb conveys almost no actionable information for a tool that returns a data set.

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?

An output schema exists, so return values need not be spelled out, but the description still fails to convey what category of related instruments is returned or any constraints on the input. For a lookup tool with one required param, this leaves a real gap in invocation confidence.

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 'quote' parameter is documented with a concrete format example (AAPL:NASDAQ). With only one fully-documented parameter, the schema does the work and the baseline of 3 applies; the description contributes no additional meaning.

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 'Google Finance related instruments' restates the tool name without a verb or a specific resource. It gives no indication of what the tool returns or how it differs from the many sibling tools (google_finance_quote, google_finance_ticker, google_finance_company, google_finance_context), leaving the agent to guess.

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?

There is no when-to-use guidance, no statement of prerequisites, and no named alternative among the google_finance_* siblings. The agent receives no basis for choosing this tool over google_finance_quote or google_finance_ticker for a given symbol.

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