start_diagnosis

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

The description adds meaningful behavioral context beyond the annotations: it tells the agent the session is 'bounded' and 'secret-redacted'. Since annotations only indicate readOnlyHint=false and destructiveHint=false, these descriptors help clarify the operational nature of the tool. It could disclose side effects more fully, but the core behavior is adequately conveyed.

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, well-structured sentence with no filler or redundant restatement of schema details. Every word earns its place and the most important behavioral descriptors are front-loaded.

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?

With 100% schema coverage and an output schema present, the description plus schema provide enough information to invoke the tool correctly. The main missing element is explicit lifecycle guidance relative to sibling tools, but that gap is already captured under usage_guidelines.

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 all three parameters are already fully documented in the schema. The description adds no additional parameter-level meaning, but given the complete schema coverage, no further compensation is required.

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 clear action ('Create') and a specific resource ('bounded, secret-redacted local development diagnosis session'), which conveys what the tool does and distinguishes it from the sibling read/analysis tools. It is not tautological, though 'diagnosis session' could be slightly more explicit for an agent unfamiliar with the domain.

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 gives no guidance on when to use this tool versus siblings like run_preflight, prepare_probe, or execute_probe. The agent must infer from the name and context that this is the initial step of a diagnosis lifecycle, but no explicit routing is provided.

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