set_flag

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It only says 'add or remove' but does not explain the effect of the 'value' parameter (whether true adds and false removes), nor any side effects like persistence, authentication requirements, or error conditions. This is a significant gap for a mutation tool.

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?

The description is a single, concise sentence that is easy to parse and front-loads the core purpose. However, it lacks any structural breakdown of parameters or usage, but that's a completeness issue, not a conciseness one. It earns a 4 for being appropriately sized.

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 tool has 6 parameters, no output schema, and no annotations, yet the description provides only the function's purpose and flag list. It does not cover parameter semantics, return values, or any edge cases, making it inadequate for an agent to call it correctly without additional schema documentation.

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?

The schema has 0% description coverage, and the description does not compensate. It fails to explain the meaning of 'uid', 'uids', 'value', 'folder', or 'account'. Even the list of flags is not explicitly tied to the 'flag' parameter. An agent would have to guess the semantics from parameter names and defaults, which is insufficient.

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 clearly states the tool's function: adding or removing an IMAP flag, and enumerates the valid flag values. This distinguishes it from generic message operations, though it doesn't explicitly differentiate from mark_read, which could be seen as a subset. Still, it's specific enough for an agent to understand the core purpose.

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 provides no guidance on when to use this tool versus alternatives like mark_read or delete_messages. There is no mention of exclusions or conditions, so an agent would have to infer usage from the function name and description, which is insufficient.

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