things_capabilities

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

Annotations already indicate readOnlyHint, idempotentHint, and non-destructive behavior. The description adds a useful behavioral consequence: unavailable features cannot be invoked, which sets the expectation that this tool reveals callable capability status. This complements the annotations without contradicting them.

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?

Two concise sentences with no filler. The first sentence front-loads the action and scope; the second sentence adds a practical implication. Every word earns its place.

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 zero-parameter, read-only capability tool with an output schema already present, the description is complete. It tells the agent what to expect, warns that unavailable features cannot be invoked, and leaves return structure details to the output schema.

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 tool has zero parameters, so the input schema places no burden on the description. The description correctly focuses on the output semantics: implementation and verification status of every operation family. This matches the 0-parameter baseline of 4.

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 uses a specific verb ('Read') and names the exact resource ('implementation and verification status of every operation family'). It clearly differentiates this from the sibling tools by focusing on capability/availability rather than individual item operations or health checks.

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 this tool should be used before invoking operations, since unavailable features cannot be invoked. However, it does not explicitly state when to prefer this over things_health or things_request_status, nor does it name any alternatives or exclusions.

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