failed_commands

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

Beyond annotations (readOnlyHint, idempotentHint, destructiveHint), the description adds behavioral details: the need for a shell hook, legacy behavior, ordering (newest first), and scope (local index only). No contradictions with annotations.

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?

The description is three sentences with no redundancy. Each sentence serves a purpose: stating the function, describing optional filtering, and listing constraints. It is front-loaded with the most critical information.

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 simple list tool with two well-documented parameters, the description covers purpose, constraints, filtering, and prerequisites (shell hook). Output schema exists for return values. Minor gap: no mention of what happens if hook is missing, but that is acceptable.

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% with clear descriptions. The description adds minor value by restating the filter option in prose ('optionally restrict to commands after a given epoch-millisecond timestamp') and mentioning ordering, but the schema already defines the parameters adequately.

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 clearly states the tool lists recent failed commands (non-zero exit) as a quick feed. It uses specific verb 'lists' and resource 'failed commands', and distinguishes from siblings like search_history by emphasizing its scope and immediacy.

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 provides explicit usage context: read-only, requires shell hook for exit-code capture, legacy entries lack exit codes, and results are newest first and local index only. It doesn't explicitly name alternatives but implies when to use this tool.

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