start_scan

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

With no annotations, the description carries the behavioral burden. It adds meaningful detail that omitting branch selects the project default, but it does not disclose whether the scan runs asynchronously, what side effects occur, or what response to expect beyond the provided output schema.

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?

Two short sentences, with the core action first and the optional-branch rule second. Every word earns its place and no schema information is repeated.

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 two-parameter tool with an output schema, the description is nearly complete: it identifies the required project context and the optional branch behavior. It falls short only in not clarifying asynchronous execution or common failure modes, which are useful but not essential for invoking the tool.

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 0%, so the description must compensate. It explains only that branch is optional and defaults to the project default; project_id is only glossed as belonging to an existing project and lacks guidance on how to obtain or validate it.

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 states a specific verb and resource: 'Start a security scan for an existing project.' This clearly differentiates it from sibling list/get/mark tools, which are about viewing or annotating scans rather than initiating them.

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 implies the use case (starting a scan for an existing project) and the optional branch behavior, but it never explicitly contrasts this tool with alternatives such as list_scans or get_scan. There is no when-not-to-use or alternative guidance.

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