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

Annotations already declare readOnly, idempotent, and non-destructive behavior, so the bar is lower. The description goes beyond this by disclosing a specific access-control requirement (access right on EVERY robot) and an important failure mode: returns a refusal naming the missing-robot and compares nothing. This is genuinely valuable operational context.

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 two succinct sentences with no filler. It front-loads the core purpose and comparison topics, then adds the access-control caveat. Every sentence contributes information not already in the structured fields.

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 one simple parameter, clear annotations, and no output schema, the description is reasonably complete. It explains the scope, supported cardinality, access prerequisites, and failure behavior. The only notable gap is the lack of robot_ids serialization format, which prevents a perfect score given the absence of parameter-level schema details.

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?

The input schema describes only 'robot_ids' as a string with no description. The description adds semantic meaning by indicating that the parameter must encode 2 to 5 robots and that access rights are checked per robot, but it does not clarify the expected string format (e.g., comma-separated IDs, JSON array, repeated delimiters). This partial compensation justifies a middle score.

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 a specific action ('Compare 2 to 5 robots side by side') and specifies the exact comparison dimensions (software BOM, TCO, jurisdiction exposure, lock-in, export control risk). It is also easily distinguished from sibling tools like hardware_compare_robots and mechanical_compare_robots because it explicitly mentions 'software' and those dimensions.

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 clear context for use: comparing a bounded set of robots on software-related criteria. It also states an explicit precondition (access right on every robot) and describes failure behavior. It does not explicitly name alternatives, but the sibling tool names and the 'software' qualifier make the intended use vs hardware/mechanical variants clear.

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