record_source

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

The description discloses the write behavior ('Writes under .agentpack/'), the caching mechanism (stores content hash with summary, reusable until file changes), and the durable conclusion nature. These details add meaningful context beyond the annotations, especially given destructiveHint=true.

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 concise and front-loaded: a clear purpose statement, followed by usage guidance and a storage side note. Every sentence carries useful information without fluff or repetition.

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 simple parameter set, absence of output schema, and provided annotations, the description is complete: it states what it does, when to use it, where it writes, and the cache invalidation behavior. There are no significant gaps in understanding how to invoke and use the tool.

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 the baseline is 3. The description adds extra meaning by explaining that 'summary' is always expected with a fallback to a generic 'Reviewed source.' It also clarifies how the summary is used with the content hash, providing value beyond the schema.

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 a specific verb ('Record') and resource ('source file in the Source Cache'), explaining the caching mechanism and reuse. It distinguishes itself from sibling tools like record_decision and record_dead_end by focusing on source files and content hashes.

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?

Explicit guidance is given on when to use ('Call after inspecting an important file when the conclusion is reusable') and when not to ('do not record every file read'), plus when to re-record ('only when the conclusion itself changed'). This provides clear context for selecting this tool over alternatives.

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