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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds cost (0.003 USDC) and enumerates required fields, which is useful, but does not explain conflict behavior or how the computation is used. With annotations covering safety, this is an acceptable addition.

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?

Very concise, but the three semicolon-separated clauses are poorly structured and front-loaded with a requirement rather than the tool's purpose. The information could be delivered more clearly in the same length.

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 a tool with one complex array parameter, no output schema, and annotations that cover safety, the description is incomplete: it does not explain return values, how policies are evaluated, or the significance of 'restrictive cap' and 'shared actions'.

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%, so the description must provide semantics. It lists the required fields ('policy identity, subject, action, lifetime and valid decisions') which maps to the schema's nested required fields, adding some meaning. However, it does not explain the array structure, min/max limits, or the meaning of each field beyond renaming.

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 computation ('compute the restrictive cap and shared actions'), which is a clear verb+resource, but it is preceded by a requirement list and lacks a clear statement about evaluating policies or how it relates to sibling tools. It is not a tautology, but the purpose is not front-loaded.

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?

No guidance on when to use this tool versus alternatives like tool_call_policy_guard or preflight. The precondition list ('Require policy identity...') is a schema requirement, not usage guidance.

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