visualize_trend

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

The description explicitly states 'Read-only', and annotations already provide readOnlyHint=true and openWorldHint=true, so there is no contradiction (which would have been a 1). The description adds value by listing the return artifact types (chart-ready series, Teams Adaptive Card, markdown table, summary) and confirming real-time behavior, which goes beyond what annotations offer. It doesn't disclose rate limits or scale constraints, but for a read-only visualization with strong annotation coverage this is adequate.

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 a single well-structured block of two sentences, front-loading the core purpose before listing output formats. Every clause contributes value—the purpose, the example, the output list, and the read-only assurance. Zero wasted words.

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?

Given that there is no output schema, the description helpfully enumerates what the tool returns (chart-ready series, Teams Adaptive Card, markdown table, summary), which compensates for the missing structured return info. The schema covers all parameters at 100%. However, for a 'real-time' visualization tool it doesn't clarify pagination, how many data points are returned per interval, or limits on the date range, leaving minor gaps for a tool of this complexity.

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 all five parameters are documented in the schema itself, which sets a baseline of 3. The description adds marginal value with the query span-filter example ('ONLast 30 days') and reinforces the default for interval/day/date_field in the schema. However, it does not add semantic meaning beyond the schema's parameter descriptions, so it does not exceed baseline.

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 uses a specific verb ('Build') with a clear resource ('a real-time trend line of ServiceNow record counts over time') and even gives an example ('incidents opened per day'). It also enumerates the chart-ready output formats (series, Teams Adaptive Card, markdown table, summary), which strongly distinguishes it from visually similar siblings like visualize_aggregate and trend_query. It further asserts read-only status.

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 provides a clear context for use (counting records over time) with a concrete example, and the query parameter guidance ('Recommended: a span filter... e.g. ONLast 30 days') adds practical usage direction. However, it does not explicitly state when NOT to use this tool or name alternatives (e.g., when to prefer visualize_aggregate or trend_query instead), so it stops short of a full 5.

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