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

No annotations are supplied, so the description carries the full burden, and it discloses nothing: no data source, update cadence, units, whether the call is a read, whether results are cached or rate-limited, and no indication of return shape. The word 'シグナル' even implies derived/computed output without explaining what that means.

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?

It is short, but shortness here is under-specification rather than conciseness: a single fragment with no lead sentence stating the action or the return. Nothing is front-loaded because there is essentially no content to front-load.

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?

For a tool with a required, undocumented identifier parameter, no annotations, and no output schema, the description would need to explain what 'series' accepts and what comes back. It does neither, so an agent cannot reliably invoke this tool from the definition alone.

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% and the sole required parameter 'series' is completely unexplained — no format (BOJ series code vs. free-text name), no examples, no valid-value hints. The description does not compensate at all, leaving the agent unable to construct a valid call.

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 phrase '日銀・金融統計・物価指数の時系列シグナル' names the data domain (BOJ / financial statistics / price indices) and hints at time-series signals, which does distinguish it from siblings like jp_crime_statistics or jp_land_price. However, it is a bare noun phrase with no verb, so it never states what the tool actually does with that data (fetch, compute, detect anomalies?). The purpose is only inferable.

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 guidance on when to use this tool versus the many other jp_* statistics tools, and no mention of prerequisites, data frequency, or coverage period. The agent must guess based on the topic keywords alone.

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