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 genuinely new context: the 0.002 USDC cost and the fact that all three caps are hard-enforced. However, it does not say what happens on violation (raise, block, return verdict) or what the response contains.

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 compact sentence with the core detection/enforcement behavior front-loaded and the price disclosed last. No filler, though the semicolon-chained phrasing is dense.

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 nested object inputs, two required params and no output schema, the description omits the return contract and the consequence of tripping a cap, which an agent needs to sequence calls correctly. The cost disclosure partially compensates, but the completeness bar is not fully met.

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 the burden, and it does reasonably: 'per-step identity, token and cost counters' maps to the trace item fields (id, tokens, cost_atomic) and 'all three hard caps' maps to the policy's max_steps/max_tokens/max_cost_atomic. It stops short of naming field names or clarifying the 'atomic' unit semantics.

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 names concrete actions (require per-step identity/token/cost counters, detect repeated nodes/edges, enforce three hard caps), which tells an agent exactly what this guard does. The cycle-detection and budget-cap combination distinguishes it functionally from neighbors like concurrency_guard, though no sibling is named 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 invoke this tool, in what pipeline stage, or which alternatives (concurrency_guard, agent_budget_guard, subscription_spend_guard) apply instead. The agent must infer usage entirely from the behavior sentence.

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