render_card

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

With no annotations to lean on, the description carries the full burden and does well: it discloses truncation-with-ellipsis, silent dropping of overflow lines, the persistence key (profile, label), and a non-obvious `changed=false` idempotency signal that lets callers skip a refresh. What it omits is where the image is stored/served from and any auth or profile-existence requirement.

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?

Roughly three tight sentences with zero filler: purpose first, then the behavioral caveat, then the return contract. The `changed` flag's semantics are tucked into a parenthetical, which is exactly the right weight for it.

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 and no output schema, the description correctly covers the return payload and truncation behavior, which is the important half. It remains incomplete for a 7-parameter, 0%-documented tool: two parameters are unexplained and there is no statement of the storage target or what happens if the profile does not exist.

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 0% across 7 parameters, so the description must compensate. It meaningfully covers header, lines and footer, and gives (profile, label) a role as the storage key, but `description` and `invert_header` are never mentioned and no parameter's format or length limits are specified.

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 (render) and resource (card) and even enumerates the card's structure (header bar, body lines, footer), which is more concrete than `render_image` or `render_layout`. However, it never explicitly contrasts itself with those siblings, so the agent must infer the card-vs-image-vs-layout boundary from the names alone.

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 statement of when to choose render_card over render_image or render_layout, and no prerequisites or exclusions. The only guidance ('keep it short') is a constraint on input content rather than a routing rule, leaving selection entirely to inference.

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