flag_message

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

There are no annotations, so the description carries the full burden of behavioral disclosure. It only states the basic set/clear action and optional colour index; it does not explain side effects, whether the operation requires an existing message, whether it is idempotent, or what the response contains.

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 short and front-loaded: it states the core purpose in the first sentence and adds the optional modifier in a single second sentence. There is no redundant or distracting content.

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 simple flagging operation, the basic action and parameter schema are present, and all parameters are individually documented. However, with no annotations and no output schema, the description does not fully communicate behavioral outcomes or the relationship between flagged and flagIndex, leaving the agent to guess some edge-case behavior.

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 description coverage is 100%, so the schema already documents all parameters. The description only mirrors the optional flagIndex concept and does not add materially to the parameter semantics provided by the input 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?

The description clearly states the action ('Set or clear the flag') and the resource ('on a message'), and adds the optional flag colour dimension. It is not tautological, though it does not explicitly differentiate itself from sibling tools like mark_read.

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, and does not mention exclusions or related sibling tools. An agent would have to infer the intended context purely from the wording of the schema and sibling names.

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