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

With no annotations provided, the description carries the behavioral burden and commendably discloses the fetch action, the state change (marks it verified), the precise success condition, and the failure return (reason). It does not discuss side effects or idempotency in detail, but the main behavior is clearly exposed.

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 front-loaded sentences deliver purpose, mechanism, success condition, and failure behavior with no filler. The inline extension example adds useful config guidance rather than padding.

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 single-parameter tool with no output schema, the description is nearly complete: it explains what is fetched, what constitutes success, and what happens on failure. A small gap is that it does not explicitly describe what a successful invocation returns or mention prerequisites such as agent_card_url being configured.

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% because the only parameter, api_key, already has a complete description in the input schema. The tool description adds nothing about the parameter, which is acceptable given that the schema fully documents it.

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 and resource: re-check the A2A Agent Card by fetching agent_card_url through Duami. It also states the exact success condition (card names the agent id), which clearly distinguishes this from sibling tools like get_agent or update_agent.

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 word 'Re-check' implies use after the agent card may have changed, and the recommended capabilities.extensions snippet tells the caller how to configure the card so verification succeeds. However, it never explicitly states when to choose this over alternatives like get_agent or update_agent, nor names prerequisites such as having set agent_card_url.

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