aggregate-spans

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

No annotations are provided, so description must compensate. It mentions computing statistics but does not disclose behavioral traits like read-only nature, side effects, rate limits, authorization needs, or performance implications for large datasets.

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?

Extremely concise: two sentences and examples. Front-loaded with purpose, no redundant information.

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?

Despite good purpose clarity, the description lacks detail on return structure, behavior with missing parameters, and does not compensate for the absence of output schema. Given the tool's complexity (nested objects, multiple aggregations), more completeness is needed.

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% (per context signal), but the description lists supported aggregation types and examples. However, it does not explain the structure of filter, compute, or groupBy parameters nor their nesting, leaving gaps.

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?

Description clearly defines the tool: 'Compute statistics on APM spans' with concrete use cases ('p99 latency by service', 'error rate per endpoint', 'request count over time'). Distinguishes from sibling search-spans by contrasting aggregation vs detail retrieval.

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?

Explicitly states when to use ('Use for ...') and directs to search-spans for detail. Does not list all alternatives but provides clear context for APM span aggregation.

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