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

Annotations already disclose write/destructive/openWorld status, yet the description adds two genuinely useful facts beyond them: the return value ('Returns the new list with its id') and the authorization requirement ('Needs edit access to the board'). It does not discuss the destructiveHint implication, but the added auth and return context is real value.

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?

Three tight sentences, front-loaded with the action, each carrying distinct information (what it does, the first-flag behavior, the return value, the permission requirement). No 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?

For a mutation tool with no output schema, the description covers the return value, the positioning option, and the required access level, and annotations cover the safety profile. Minor gap: no mention of where in a board workflow this fits or error conditions, but an agent has enough to call it correctly.

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 33%, so description must compensate, and it partially does by explaining the 'first: true' placement behavior and referring to the board. However 'title' and 'boardId' carry no added meaning beyond the schema, leaving one required parameter effectively undocumented.

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 (Adds) and resource (a list/column to a board), and even disambiguates the domain term 'list' as 'column'. An agent can distinguish this from create_board, create_task, update_list, and duplicate_list purely from the text.

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 explains the positional behavior of the new list ('at the end or, with first: true, before the other lists'), which is a usage hint, but it does not name sibling alternatives or state when-not to use it. Usage is implied rather than explicit.

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