Attach to Card

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

With no annotations, the description carries the full behavioral burden. It usefully discloses that https:// stores a link, file:// uploads from TRELLO_ATTACH_ROOT and is refused when unset, and data: URLs upload inline data. It omits broader mutation effects or permissions, but covers the critical source-dependent behavior well.

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?

Front-loads the core action in the first clause, then enumerates the three source behaviors compactly. Every sentence earns its place and there is no redundant or vague 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?

The 4-parameter schema is fully documented and the description explains the most error-prone parameter. It does not describe return values, but no output schema exists and the schema handles name/mimeType defaults. It is nearly complete for calling the tool 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 100%, so the baseline would be 3. The description adds meaningful semantics for the source parameter by explaining the behavior of each URL scheme, including the file:// root requirement and refusal condition, going beyond the schema's format list.

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 and resource: 'Attach something to a card.' The source-scheme details clarify what 'something' can be. It does not explicitly differentiate itself from sibling tools such as download_attachment, but the purpose is clear enough to route correctly.

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?

Provides operational guidance for the source parameter, including when file:// is refused. However, it does not say when to use this tool versus alternatives or mention prerequisites such as card existence or permissions. Usage is implied rather than explicitly framed.

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