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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint, covering the safety profile. The description adds valuable behavioral context: threshold default (0.7), returning the two most likely labels, and returning an index for mapping. It also explains the practical meaning of low confidence. This goes beyond annotations without contradicting them.

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?

Three sentences with zero fluff. The core action and return behavior are front-loaded, followed by usage context and mapping detail. Every sentence earns its place, and the structure guides the agent from what it does to why it exists.

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 the tool's moderate complexity (4 parameters, 2 required, output schema present), the description covers all critical aspects: threshold behavior, return contents (two labels, index), and how to interpret results. An agent has everything necessary to call it correctly without additional inference.

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 the schema already documents all parameters, defaults, and constraints. The description adds no additional parameter semantics beyond what the schema provides, such as clarifying the 'below' threshold's role or the 'labels' list's purpose. It meets the baseline of 3 for high coverage but does not elevate further.

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 states a specific verb and resource: 'Classify up to 1,000 texts and return only the ones whose confidence fell under a threshold'. It clearly distinguishes from siblings by framing this as a post-hoc review tool after bulk classification, which differentiates it from classify_texts or classify_multi_label. The purpose is unambiguous and actionable.

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 explicitly gives context: 'Use this after a bulk classification to decide which items deserve your own attention'. It explains why this is useful (confident answers can be trusted) and how it maps back (returns index). It does not list exclusions or alternative tools by name, but the usage niche is clear. Missing explicit 'when not to use' guidance prevents a 5.

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