get_agent_card

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

No annotations are provided, so the description carries full burden. It does not disclose behavioral traits such as whether the tool is read-only, what happens if the agent_id is invalid, or if any authentication is required. It only repeats the purpose.

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 a single sentence with 15 words, front-loaded with the main action and resource. Every word adds value; no redundancy or filler.

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 covers the tool's purpose but lacks details on return format, error handling, or edge cases (e.g., nonexistent agent). Given no output schema and simple parameters, it is adequate but could be more complete by stating that it returns the full card object.

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% with each parameter already described (agent_id: ERC-8004 token ID; chain_id: Chain ID). The description adds no new meaning beyond the schema, so it meets the baseline of 3.

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 the action ('Fetch'), the resource ('single agent's full ERC-8004 registration card'), and lists specific contents (name, description, services, x402 support, trust models). It distinguishes from sibling tools like 'call_agent_with_payment' and 'find_agents_by_skill' by focusing on fetching a single agent's detailed card.

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 when to use this tool (to fetch a single agent's details), but it does not explicitly state when not to use it or suggest alternatives. For example, it could mention that for searching by skill, one should use 'find_agents_by_skill', but it does not.

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