Replay a recorded browser session (HAR) with CSRF/token auto-correlation

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

With no annotations provided, the description carries the burden of disclosing behavior. It reveals that dynamic values are detected and substituted automatically, static assets are skipped by default, and dry_run prevents actual requests. This covers the most important behavioral traits, though it doesn't explicitly state that live requests will be made during a real run.

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 three sentences, front-loaded with the primary action, followed by a concise explanation of the auto-correlation mechanism and then parameter usage notes. Every sentence earns its place with no redundancy or fluff.

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?

Given the tool's complexity (4 params, nested object, no output schema), the description covers the essential behavioral and usage aspects: the purpose, the auto-substitution mechanism, default asset skipping, and parameter-specific roles. It doesn't cover failure modes or redirects, but the core functionality is well-specified.

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?

The schema descriptions already cover all parameters (100% coverage), so baseline is 3. The description adds practical guidance beyond the schema: 'substitutions' for credentials/API keys, 'dry_run' for previewing. This enhances semantic understanding beyond the parameter descriptions alone.

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 specific verb and resource: 'Replays an HTTP Archive (.har) file exported from browser DevTools.' It also explains the core value-add of auto-correlating dynamic values, clearly distinguishing it from the scraping-focused sibling tools. The title reinforces the purpose with 'CSRF/token auto-correlation.'

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 clear usage context: it is intended for login flows, form submissions, and signed API calls, and explains when to use 'substitutions' (for values never in responses) and 'dry_run' (to preview). It doesn't explicitly name alternative tools, but no sibling tool overlaps with this replay functionality, so the context is sufficient.

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