heap_snapshot

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

Annotations already indicate destructiveHint=true and readOnlyHint=false, but the description adds crucial specifics: it overwrites an existing file, produces a large dump (hundreds of MB), and does not modify the page. It also notes Chromium-only behavior. These details go beyond the binary annotations, giving the agent actionable expectations.

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 slightly dense but well-structured. It leads with the action, then provides default, constraints, size, overwrite behavior, and usage note in a logical flow. Each sentence adds value; although verbose, it remains efficient and front-loaded with the core purpose.

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 tool with one optional parameter and an output schema, the description is largely complete. It covers the primary purpose, default behavior, constraints, size impact, overwrite warning, and platform limitation. It does not detail the return value, but that is handled by the output schema, so no gap exists there. The only minor omission is explicit instruction on how to pass the path parameter, but constraints imply relative/full path usage.

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 0%, so the description carries the burden. It explains the default path (jevnav-heap-<timestamp>.heapsnapshot under --file-root), the requirement that the path stay inside file-root, and the default working-directory behavior. This meaningfully supplements the bare schema type string/null, though it does not describe the format for explicit path input.

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 tool's function: 'Write a Chromium heap snapshot of the current page to a file.' It specifies the output format and destination, and the purpose ('for Chrome DevTools > Memory'). It distinguishes itself from other tools by noting it is 'chromium-only' and 'changes nothing on the page', which separates it from page-mutating actions among its siblings.

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 provides explicit guidance: 'Use it to chase a memory leak, not for routine inspection.' This tells the agent when to invoke it and when not to, though it does not name specific sibling alternatives. The 'changes nothing on the page' note also clarifies it is safe for state, adding context for selection.

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