Connect SE050 hardware bridge

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

Despite annotations (readOnlyHint=false, destructiveHint=false), the description adds valuable context: 'opens a short-lived serial session; does not export private keys' and 'No SSX360_API_KEY required.' It also discloses the return shape, covering side effects and auth requirements beyond what annotations provide.

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 well-structured: purpose sentence, usage guidance, side effects, return, then parameters. It is front-loaded with the core purpose. Slightly verbose due to repeated parameter details already in schema, but every sentence serves a functional role and the organization aids comprehension.

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?

Given the tool's complexity (hardware interaction, side effects, alternatives) and the presence of an output schema, the description covers all essential aspects: prerequisites (probe before signing), exclusions, auth requirements, side effects, return format, and parameter guidance. The agent has enough context to invoke it correctly and understand outcomes.

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 100%, so the schema already documents all parameters. The description restates parameter meanings (e.g., 'reader_name: Serial port, e.g. COM3 or /dev/ttyACM0') but adds no new semantic information beyond the schema. It also includes the same security hint about MATRIXSCROLL_PIV_PIN. Baseline 3 is appropriate.

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 opens with a specific verb+resource: 'Probe AP2 Vault Card / SE050 USB CDC hardware signing bridge availability.' It explicitly distinguishes itself from siblings by stating 'Use create_envelope for signing... Do not use for verification — call verify_envelope... Prefer status to check local identity without opening USB.' This clearly identifies the tool's unique role.

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 when-to-use context ('Use before hardware signing to confirm the reader responds on the serial port') and clear exclusions ('Do not use for verification'). It names alternative tools (create_envelope, verify_envelope, status) with reasons, giving an agent strong decision support.

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