Set breakpoint

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

Annotations only state readOnlyHint=false and destructiveHint=false, so the description legitimately carries the burden of explaining semantics. It adds real behavioral detail beyond the schema: source-map remapping behavior, 1-based line/column convention, and the fact that logMessage interpolates {expr} and does not pause. There is no contradiction with annotations.

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 compact and front-loaded with the core action, then packs high-value details into a few short sentences. Nothing is redundant or filler, though the density of the source-map sentence could be streamlined. It earns a strong score without being maximally minimal.

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 6-parameter debugging tool with full schema coverage and no output schema, the description plus schema are sufficient for an agent to call the tool correctly. It covers the non-obvious file resolution rule, source map remapping, coordinate base, and logpoint behavior. It only lacks an explicit note about when sessionId is required, but that is already in the schema.

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 baseline is 3. The description does restate some schema details (file resolution, 1-based line) but adds minimal new parameter semantics beyond what the schema already documents. It does not explain the condition parameter or sessionId semantics beyond the schema, so it stays at the baseline.

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 opens with a specific verb and resource: 'Set a line breakpoint with Debugger.setBreakpointByUrl.' It clearly distinguishes this from siblings like debug_remove_breakpoint and debug_list_breakpoints by scoping to line breakpoints and explicitly mentioning the CDP method. The file resolution model and logpoint variant add further precision.

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 when to use the tool – when you need to set a line breakpoint or a logpoint, and it gives useful context about file paths, package specifiers, source maps, and 1-based coordinates. However, it never explicitly contrasts itself with alternatives such as conditional breakpoints vs. debug_pause/debug_continue, or when sessionId is needed. Usage guidance is clear but not explicit about when-not-to-use.

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