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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds behavior beyond that: cardinality and return scope ('One figure per ticker; no price history is returned') plus the dual-currency framing. It does not mention rate limits or failure modes, but for a read-only lookup with full annotation coverage this is solid.

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?

Front-loaded with the core definition, then usage, then the alternative, then the base parameter. Every sentence carries weight, though the parenthetical aside about 'base' interrupts the flow of the usage guidance and could be merged more cleanly.

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-value explanation is not strictly required, and the description still volunteers the key cardinality fact. The phrase 'in the base currency and in its own' combined with 'One figure per ticker' is mildly ambiguous about whether two amounts or one are returned, but the output schema resolves it.

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 are already documented, including the base default and the 50-ticker cap. The description's 'base sets the currency of the converted price (default USD)' largely restates the schema rather than adding syntax or format detail, so the baseline of 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+resource+scope: 'The latest daily close for each ticker, in the base currency and in its own, with the date.' It also explicitly distinguishes itself from the closest sibling ('for the history and figures of one asset use asset_info'), so an agent can route without opening either 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?

Gives a concrete when-to-use case ('turn a number of shares into an amount before a measurement') and names the alternative tool for the contrasting case ('asset_info'). Nothing is left to inference about which of the two to pick.

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