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

Annotations already cover the safety profile (readOnlyHint, destructiveHint=false, openWorldHint=false). The description adds a genuinely new trait — 'Non-billable' — and characterizes query behavior (free text is 'ranked against name and description'), which the structured fields do not convey.

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?

Front-loaded purpose sentence followed by a compact numbered list of query forms; every clause carries information and none is redundant. Appropriate length for a two-parameter tool with three distinct modes.

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 read-only search tool with no output schema, the description covers invocation modes, the result kind ('get its definition'), the max_results caveat, and cost. Nothing an agent needs before calling is missing, and sibling list_skills is named for the discovery edge case.

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 coverage is 100%, so baseline is 3. The description goes slightly beyond the schema by giving a concrete free-text example ('cancel run') and stating the ranking basis, clarifying how the query parameter actually behaves rather than just restating the accepted forms.

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?

States a specific verb+resource: 'Find a tool listed here... and get its definition', with the explicit motivation 'instead of guessing its name'. This distinguishes it cleanly from siblings like list_skills or get_live_flow, which retrieve different resources.

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?

Gives the selection condition up front ('instead of guessing its name'), enumerates all three query modes, and routes the agent to list_skills for the skill names. Explicit when-to-use plus a named alternative, with nothing left to inference.

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