get_card_by_number

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

With no annotations, the description carries the full transparency burden. It states return behavior ('full card details including assignees and labels') and error handling ('Returns an error dict if no card is found'), which goes beyond the schema and provides useful behavioral context. It doesn't mention permissions or rate limits, but for a plain lookup this is reasonably transparent.

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 compact, front-loaded sentences. The first sentence immediately states the action and resource; the second adds optional scoping and return/error behavior. Every word earns its place with no redundancy.

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?

Given the low complexity (2 params, no enums, existing output schema), the description adequately covers purpose, parameter semantics, and error behavior. The optional project scoping is also covered. It is complete for an agent to select and invoke the tool correctly without additional context.

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% and the description fully compensates by explaining 'number' as a visible card number (e.g., #15293) and clarifying that project_id is optional scoping. This adds meaning beyond the bare integer/null schema types, making parameter purpose clear.

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 uses a specific verb ('Look up') + resource ('a card') + scope ('by its visible card number'), clearly distinguishing it from sibling tools like get_card which likely queries by internal ID. The example (#15293) further clarifies the lookup mechanism.

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 clearly identifies the retrieval context (by visible card number, optionally scoped to a project) without explicitly naming alternative tools. It implies usage for when the visible number is known and provides optional scoping, which is actionable but lacks explicit when-not/exclusion guidance.

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