register_diagnostic

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

Annotations are minimal (idempotentHint: false, destructiveHint: false). The description adds that diagnostics are 'fixed' and 'deliberate', implying immutability, but does not disclose side effects, uniqueness constraints, or error conditions.

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?

Three concise sentences with no fluff. Front-loaded with the primary action and context, each sentence earns its place.

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?

Provides key context for a registration tool (when to use, purpose) but missing details about uniqueness, return value (output schema exists but undocumented), and error handling.

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 low (20%). The description does not explain individual parameters like 'unit', 'direction', or 'id', relying on schema defaults without adding meaningful context.

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 ('Register a named, fixed, measurable metric') and its purpose ('comparability across experiments'), setting it apart from siblings like list_diagnostics and record_diagnostics.

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?

Explicitly says 'Do this before predicting on a metric', providing clear temporal usage context. No explicit exclusions or alternatives, but the description implies when it is appropriate.

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