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

Annotations already carry the safety profile (destructiveHint=false, openWorldHint=true, idempotentHint=false), so the bar is lower. The description adds useful context about the output shape, but since an output schema exists that content is largely redundant, and it never addresses the non-idempotent hint or that estimates may vary between calls due to external calibration.

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?

Four short sentences, zero filler, and the core purpose and return shape are front-loaded before the routing guidance. Every sentence earns its place.

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?

An output schema exists, so the description needn't document return values, and it correctly covers purpose, triggering condition, and the sibling alternative. Nothing an agent needs to call this correctly with a valid modules list is missing.

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 itself supplies examples ('Tenant onboarding flow with SSO integration'). The description adds only the framing that items are short deliverable descriptions, which the schema already states. Baseline 3 is appropriate where the schema does the heavy lifting.

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 verb and resource ('estimate the size and cost of a specific list of work items') and enumerates what comes back: per-item Delivery Units, a total, an indicative cost, and a recommended plan size. It also explicitly distinguishes itself from the sibling create_delivery_plan, so an agent can route without opening either schema.

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?

Gives both a positive trigger ('when the user has already broken the work into specific items and wants sizing') and a negative one with a named alternative ('when the user describes an overall goal without a breakdown, use create_delivery_plan instead'). This is exactly the when/when-not/alternative structure that enables correct selection.

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