Shares outstanding

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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds real behavioral context: the return shape (date + shares outstanding), that only the most recent `limit` points come back, and the 18-month default window. It doesn't mention pagination beyond limit or rate limits, so it stops short of a 5.

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?

Three tight sentences with zero waste: purpose first, then return shape, then the limiting constraint and its remedy. The most actionable caveat (18-month window) is front-loaded enough to be caught before calling.

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 needn't explain return values in depth, and it covers purpose, windowing, and limit behavior adequately. The only gap is the absence of routing guidance relative to sibling history/fundamental tools, which is minor given the clear resource name.

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 the schema already documents every parameter. The description's notes on limit being most-recent-only and start defaulting to 18 months largely restate what the schema says, adding little new meaning. Baseline 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 and resource — 'Get the shares-outstanding history for a Yahoo symbol' — which is distinct from siblings like get_financials and get_holders. An agent can tell at a glance this returns a time series of share counts, not a snapshot.

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 description gives conditional guidance for the start parameter ('pass one for anything older' than 18 months), which is useful. However, it never names an alternative tool or says when to prefer get_shares over get_financials/get_holders, so usage is implied rather than stated.

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