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

Annotations already declare readOnlyHint, openWorldHint, idempotentHint, and destructiveHint. The description adds valuable context beyond those: it uses live/current metadata and explicitly does not fabricate a composite score. No contradiction 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?

A single focused sentence that front-loads the action and bounds, then appends the key caveat. There is no filler or redundant restating of the schema.

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?

The description is enough to understand the core operation, but with no output schema it does not clarify what a comparison returns or how `probe` affects the result. It is adequate but not fully complete for an agent invoking it blind.

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?

With 0% schema description coverage, the description must carry parameter meaning. It clarifies that sml_ids represents the two-to-five capabilities being compared, but it never explains the probe boolean or the expected string format. Partial compensation, with a clear gap around probe.

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 a specific verb ('Compare'), a clear resource ('capabilities'), and a numerical scope ('two to five'), then adds an explicit constraint ('without fabricating a composite score'). This makes it easy to distinguish from sibling tools like inspect_capability or recommend_capability.

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 implies the tool is for comparing multiple live capabilities, but it does not state when to prefer it over siblings or provide exclusion criteria. There is no explicit when-to-use or when-not-to-use guidance, so the context must be inferred.

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