get_shares_history

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is fully covered. The description supplements this by disclosing the return shape ('shares at several points and the total change') and the dilution/buyback framing, but does not add richer behavioral context such as data source or freshness.

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-loads the purpose before the Args/Returns blocks, and the overall length is proportionate. The Args section partially repeats schema information, which is minor slack but not wasteful enough to penalize heavily.

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 present the description need not detail returns, yet it summarizes them helpfully; params and safety are all accounted for. The only genuine gap is the absence of usage guidance against alternatives, which limits it below a 5.

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 0%, so the description must carry the burden, and it does document both parameters ('ticker: Stock ticker symbol', 'years: How many years back (default 3)'). The ticker gloss is somewhat tautological with its name, but the years gloss adds the 'back' direction and confirms the default that the schema already encodes.

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 and resource ('Get shares outstanding over time') and adds an interpretive gloss ('dilution or buybacks') that clarifies why an agent would want it. It is reasonably distinct from siblings like get_stock_splits or get_major_holders, though it does not explicitly name those alternatives.

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?

The parenthetical '(dilution or buybacks)' implies the analytical context in which this data is useful, but there is no explicit when-to-use statement, no when-not-to-use, and no named alternative among the many sibling tools. Usage is only weakly implied.

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