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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, covering the safety profile. The description adds 'free' and 'does not charge', which is a useful cost behavior not in annotations, but it does not describe return format, permissions, or what a preflight actually validates.

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?

Two short sentences with no filler; the non-execution/non-charge statement is front-loaded in second position to clarify scope. The first sentence reads as a compact keyword list but remains efficient.

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?

For an 8-parameter tool with a nested object and no output schema, the description is thin. It does not explain what the preflight returns, how to supply the service input, or the meaning of most parameters, leaving substantial gaps for correct invocation.

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% with 8 parameters (including a nested 'input' object). The description gestures at 'network' and 'budget' but never maps or explains any parameter, leaving serviceId, intentId, protocol, correlationId, idempotencyKey, and the nested input entirely undocumented.

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 function: a free service-specific preflight covering schema, network, budget and economic checks. It clarifies the scope and the non-executing nature, which helps distinguish it from phion_execute, though it does not explicitly name sibling tools.

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 implied rather than stated — 'It does not execute or charge' hints that this is a safe step before execution, but there is no explicit 'use before phion_execute' or 'when not to use' guidance. The agent must infer the context.

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