card_build

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

No annotations exist, so the description carries the full burden. It does disclose two useful traits — output is unsigned and derived from a template — but says nothing about permissions, whether it persists a file, error behavior for unknown faces, or what the agent gets back.

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; every clause (card shape, face list, template source, unsigned status) contributes information.

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 annotations, no output schema, and a nested `overrides` object, the description is too thin: it never explains what the built card contains, where it is written, or how overrides merge with the template. An agent can pick the tool but cannot confidently invoke it with overrides.

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 0%, so the description must compensate. It does add real meaning for `face` by enumerating the four valid values (the schema gives only an unconstrained string), but `overrides` — a nested object, the most semantically opaque parameter — is not mentioned at all.

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?

Names a specific verb (Build) and a specific resource (A2A v1.0-shaped Agent Card) scoped 'from its template' for a named set of faces. The trailing 'Unsigned' implicitly separates it from card_sign, but the sibling is never named, so differentiation is inferred rather than stated.

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?

Usage is only implied: 'Unsigned' hints that signing (card_sign) is a separate follow-up step, and 'from its template' suggests this is the generation stage before verify/sign. There is no explicit when-to-use, when-not-to-use, or named alternative.

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