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

Annotations already declare readOnly, idempotent, non-destructive and open-world behavior, so the safety profile is covered. The description adds genuine context beyond that: it is a live snapshot ('right now') grouped per window, and results are capped at 100 rows per window. It does not say what happens when no windows are running or whether empty windows appear in the result.

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?

One front-loaded sentence that leads with the resource and scope. The trailing parenthetical duplicates the schema's own cap statement, which is mild waste but does not obscure the point.

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?

Output schema and annotations carry the return shape and safety profile, so the description need not explain them. However, for a tool whose core concept is 'scanner windows', the description never defines a window, says whether monitors must be created via save_scanner_monitor first, or describes behavior with zero running windows — gaps an agent would hit while deciding to call 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%, and the schema already explains both fields, including that extra column names come from search_scanner_columns. The description only restates the rows_per_window cap and says nothing about 'fields' semantics, so it adds essentially nothing over the schema.

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 resource ('each of the caller's running scanner windows') and what is returned ('what each matches'), plus a real-time qualifier ('right now'). It implicitly separates itself from status/listing tools, but never names a sibling such as get_scanner_status or scan_market, so differentiation still requires schema inspection.

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 when-to-use guidance and no named alternative. An agent cannot tell from the description when to call this versus get_scanner_status, get_scanner_chart, or scan_market, and the caller's prerequisites (does a scanner window need to be running first?) are left unstated.

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