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

Annotations already declare non-idempotent, non-destructive, closed-world behavior; the description adds the meaningful 'why' — atomicity plus 'Never retry blindly', which implicitly warns that a retried decrement double-applies. It does not disclose what happens on underflow when a minimum clamp is set (error vs. saturation) or whether a decrement creates a missing key, so it falls short of full disclosure.

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, front-loaded sentences with no filler; the safety warning is placed at the end where it reads as an imperative. The compressed phrasing ('optional clamps and bounded history') borders on terse but stays parseable.

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?

This is a mutating, non-idempotent tool with five parameters, zero schema descriptions, and no output schema. The definition omits clamp edge-case behavior, what a history-enabled call returns, and error conditions — gaps an agent needs before invoking it correctly.

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 carry all parameter meaning, and it only gestures at three of five: 'clamps' (minimum/maximum) and 'bounded history' (history). The core 'by' step amount and the 'key' format constraints are never explained, and clamp semantics remain ambiguous.

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 ('Atomically decrement a signed 64-bit counter') plus the optional modifiers (clamps, history). It is clearly distinguishable from the sibling increment_counter by direction, though it never names that sibling explicitly.

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?

There is no statement of when to choose this over increment_counter or how to handle a missing key. 'Never retry blindly' is a retry caution, not usage routing, so an agent gets no explicit when/when-not guidance.

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