get_equities_bars_daily_am

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

The annotations already declare safe operation (readOnlyHint=true, destructiveHint=false), so the description goes beyond by disclosing update and expiry times (updated around 12:00 JST; expires around 6:00 JST next day). This temporal behavior is not available through annotations or schema, adding genuine value. No contradiction.

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 description is well-organized into clear sections: purpose, usage keywords, update/expiry schedule, alternative tool, supported plan, and args. Every sentence contributes unique information, and the most critical facts (what it does, when to use it) are front-loaded. No redundancy.

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 only one optional parameter, an output schema present, and extensive annotations, the description covers all essential aspects: purpose, usage scenarios, schedule, alternative, plan restriction, and parameter semantics. It is complete for an agent to select and invoke the tool correctly.

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?

The input schema has 0% description coverage, but the description fully compensates with a dedicated Args section. It explains the code parameter's format (5 digits), the special behavior for 4-digit codes (ordinary shares only), and the effect of omission (retrieve all stocks). This is more than sufficient for the single optional parameter.

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 clearly states the tool returns 'Today's morning session OHLC bars' and includes Japanese equivalents, making the resource and verb explicit. It also distinguishes itself from the sibling tool get_equities_bars_daily by specifying that it is for current morning session data, not historical.

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 provides explicit usage contexts ('Use for 前場, 前場終値, 午前の株価, morning session OHLC, 前場引け') and names the alternative for historical data ('get_equities_bars_daily'). It also notes the premium plan requirement, which is a key access constraint.

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