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

Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely new behavior: no charge is incurred, credits are not dollars, allowance is rechecked at execution, and operation lookup requires jobs:read plus originating-key ownership. It also discloses edge-case semantics (child jobs excluded, missing ledger evidence reported as unknown).

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?

Front-loaded with the core purpose, then the optional-parameter behavior, then caveats. Dense but every clause carries information; the telegraphic phrasing ('absent ledger evidence stays unknown') is slightly compressed but not wasteful.

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, and the description still covers auth prerequisites, exclusion rules, unknown-evidence handling, and the execution-time recheck. For a single-optional-parameter read tool, nothing an agent needs to call it correctly 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 coverage is 100% and the schema already documents operation_id, yet the description adds real meaning: it returns known primary generation credits, returns zero for local draft edits, excludes child jobs, and requires jobs:read and originating-key ownership. That goes beyond the schema's terse field note.

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 ('Inspect') and a precise resource set: generation and knowledge-search credit estimates, organization allowance, and this key's period usage/cap. No sibling tool covers credits or usage, so the agent can distinguish it immediately from the get_* family.

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 explains what the optional operation_id path yields and its exclusions, which implies when to pass it, but it never states the primary when-to-use case (e.g. check allowance before starting a generation) or names an alternative. Usage is inferable rather than explicit.

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