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

Annotations already declare readOnly=true, destructive=false, and openWorld=true, so the safety profile is covered. The description adds the useful structural fact that the output contains two separate answers (marketplace signature vs. the agent's own), but says nothing about failure modes such as an unsigned or nonexistent card.

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 front-loaded sentence with no filler; the most important fact (who vouched, and that there are two separate signatures) comes first.

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?

With no output schema, the description carries more burden, and it does sketch the return shape (two separate signature reports). However, it omits what happens when no card exists or when attestations are missing, leaving edge-case behavior unclear.

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% and the sole parameter agentId is documented, so the baseline is 3. The description adds no format, prefix, or source detail for the identifier beyond what the schema provides.

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?

States a specific verb ('Check') and resource (an agent's card attestation), and clarifies that it reports two distinct signatures: the marketplace's and the agent's own. It is distinguishable from siblings like get_agent and get_capability_report, though the term 'card' is domain jargon left undefined.

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?

There is no indication of when to call this versus get_agent or get_capability_report, no prerequisites, and no exclusions. The agent must infer the scenario entirely from the title.

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