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

The description discloses key behavioral traits beyond the minimal annotations: 'Points recompute periodically,' 'Not metered,' and the account requirement with a signup link. These are valuable context for an agent to understand side effects and prerequisites, which annotations alone do not provide.

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 4 sentences, front-loaded with the main purpose, and every sentence adds value (definition, parameter clarification, behavior, and prerequisite). It is appropriately sized with no filler.

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?

The description covers the core concept, key parameters, behavioral traits, and account requirement, making it sufficient for an agent to invoke correctly. However, it does not mention the return value or response structure (no output schema exists), which is a minor gap for a create operation.

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 coverage is 100%, with detailed descriptions for interval and window in the schema. The description repeats this information ('interval is hour or day; window is how far back to compute') without adding new semantics. The cross-reference to search_dataset/list_records filters is in the schema itself, so the description does not compensate beyond 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 clearly states 'Create a Trend: a saved match query bucketed over time,' using a specific verb and resource with a definition that distinguishes it from sibling tools like alert_create or keyword_create. The phrase 'bucketed over time' adds unique semantic value beyond the name.

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 clear context on what the tool does, implying when to use it (i.e., to create a time-bucketed saved query), but does not explicitly mention alternatives or exclusions. It lacks a direct 'use this instead of X' comparison, but the definition is sufficient for basic selection.

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