card_custom_field_items

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

No annotations exist, so the description bears the full burden, and 'reading' at least signals a non-mutating operation. It says nothing about permissions, pagination, or whether unset fields are omitted, but for a simple single-parameter read this is a modest gap rather than a severe one.

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 wasted words. Efficient, though the 'Use when' phrasing is slightly clipped.

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?

Adequate for a one-parameter read tool, but with no output schema and no description of returned value shape (per-field items, values, types), an agent still lacks a picture of the response.

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?

Only one parameter (cardId) and the schema documents it fully, including short-link and URL forms, so baseline 3 applies. The description adds no meaning beyond the schema.

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 ('reading') and resource ('all custom field item values currently set on a Trello card'), which distinguishes it from mutating siblings like card_custom_field_set and card_custom_field_clear. It does not, however, explicitly contrast with custom_field_get or custom_field_options.

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?

'Use when reading...' gives a trigger condition, implying it is a read path versus the set/clear siblings. No alternatives are named and no when-not guidance or prerequisites are provided.

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