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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is low. The description adds genuinely non-obvious behavior: it doesn't compute anything itself but 'Returns instructions to follow with the user's text,' telling the agent to expect a procedure to execute rather than a finished answer. No contradiction with annotations.

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?

A single dense sentence that correctly front-loads the core purpose before the enumerated sub-topics, followed by one short sentence on the return shape. Every clause earns its place, though the middle list is somewhat packed.

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 return values need not be explained; the description still helpfully notes the output is a set of instructions. It says nothing about limits or caveats for the 50k-character input, but for a single-parameter, read-only reasoning tool this is essentially complete.

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?

One parameter with 100% schema description coverage, which already explains the expected input (feature description, model, usage, current pricing). The description adds nothing about the parameter's content or the sizable 50,000-character allowance. Baseline 3 applies when 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?

The description opens with a specific verb+resource ('Work out an AI feature's unit economics and pricing') and enumerates the deliverables: per-request/per-user costs, levers, pricing options with margins, guardrails, assumptions. It is clearly distinct from adjacent tools like estimate_cost or plan_ai_launch by naming pricing/margins as its output, though it never explicitly contrasts itself with those siblings.

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?

Usage is only implied: the agent can infer this applies when a user wants pricing for an AI feature, but there is no statement of when to pick this over estimate_cost (cost estimation) or plan_ai_launch, and no prerequisites or exclusions. Adequate but leaves selection to inference.

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